The Europe '72 Overdubs (Guest Post)

Europe ‘72
Notes on Song Selections and Overdubs for the Original Album and Volume 2
By Steven Seachrist 

The final show of the 1972 tour of Europe tour took place on May 26 in London. Then the band, their crew and families headed back to the New World, armed with a huge stash of two inch wide, sixteen-track audio tape containing nearly every note played on the tour. This is saying a lot: there were about 2000 pounds of tapes, or as recording engineer Bob Matthews estimated, 17 miles of tape to listen to. Plenty of previous Grateful Dead shows had been taped in multi-track, but never on this scale. Twenty-two complete shows now rested comfortably in the vault back in California, and a live album was planned. It was originally called Steppin’ Out.

The idea was to present songs that either were completely new, or ones that had not been previously released in live form. This philosophy continued with Steal Your Face, the live album recorded in 1974, and even with Reckoning and Dead Set, the next contemporaneous live albums, recorded in 1980. The idea of repeating live song versions must have seemed ill advised at the time.

As they had with the 1971 live album Grateful Dead (commonly referred to as Skull and Roses), the band decided on some studio doctoring of the tapes. Today, this seems almost sacrilege, as we accept the raw edges of live Grateful Dead recordings just as we would at a concert. But back in 1972, the band and/or their record label wanted to present polished excerpts from the tour. They even edited out almost all of the stage banter and crowd reactions at the tops and tails of songs, making the Europe ’72 album sound even more like a live/studio hybrid.

In all, seventeen songs made the final album cut, if you count the transitional jams “Prelude” and “Epilogue” as songs. Others were considered and even overdubbed back home, but were later dropped. There are some clues as to which songs and versions almost made the cut.

In 2011, Rhino released a box set of the entire tour called Europe ’72: The Complete Recordings. No information was provided regarding which live tracks were supplanted by overdubs performed in the studio after the tour. Sometimes Jeff Norman, the audio engineer, used the studio-dubbed vocals; in other cases he recovered the original live vocals. Some of the differences are obvious, some are only apparent when comparing to circulating tapes, and others can’t reliably be sussed out. Unless Norman wants to tell what he knows, we may never be able to untangle all of the details, and I suspect he has been sworn to secrecy.

About the same time the big box hit the streets, Rhino also issued a 2-CD compilation product titled Europe ’72, Volume 2 that attempted to represent a sequel to the original album. This effort is very well thought out, and contains excellent versions of songs not present on Europe ’72. They did break the rule of “no songs previously released on earlier-recorded live albums,” but at this point no one cares about that. It’s a great listen and it really does seem like an extension of the original album.

The box set mix was used for all songs on Volume 2. No performances from earlier archival releases (Hundred Year Hall, Rockin’ the Rhein, Steppin’ Out and the 2001 remaster of Europe ’72 with bonus tracks) were used on Volume 2.

Since there is little information on exactly what overdubs were done for the Europe ’72 album, and which of them were kept on the box set, a post gathering all the known details has been needed. Here is a breakdown of what we can tell about the origins of the recordings, given the available clues. A single asterisk * indicates the version was used on the original album released in 1972, and a double asterisk ** indicates the version was used on Europe ’72, Volume 2, the compilation released in 2011. The reason I am including this later release is that some overdub work was done on at least one song that did not make the original cut.


Vocal Overdubs

April 7, 1972

Me and My Uncle ** This is apparently completely live, with no overdubs.

Not Fade Away ** This is apparently completely live, with no overdubs.

Goin’ Down the Road Feeling Bad ** This is apparently completely live, with no overdubs.

Not Fade Away (Reprise) ** This is apparently completely live, with no overdubs.


April 8, 1972

Cumberland Blues * It seems the vocals were overdubbed on this, as they are significantly more polished than other live versions from the tour. The overdubbed vocals are apparently used on the box set mix. (The original vocals have never circulated on tape; and though David Lemieux has said that they weren’t erased, they were not used for the box set.)


April 14, 1972

Bertha ** This is apparently completely live, with no overdubs.

Black Throated Wind ** This is apparently completely live, with no overdubs.

Chinatown Shuffle ** This is apparently completely live, with no overdubs.

Loser ** This is apparently completely live, with no overdubs.

Brown-Eyed Women * This lead vocal was definitely overdubbed, as a different vocal appears on the box set mix.


April 26, 1972

Dire Wolf ** This is apparently completely live, with no overdubs.

Good Lovin’ ** This is apparently completely live, with no overdubs.


May 3, 1972

Sugaree ** This is apparently completely live, with no overdubs.

China Cat Sunflower * This lead vocal was definitely overdubbed, as a different vocal appears on the box set mix.

I Know You Rider * The harmonies here are tighter than other versions on the tour, and it follows that these were probably overdubbed. The doctored vocals appear on the box set mix. The only vocals here that don’t have harmonies are on the “train” verse, and Garcia sings that in a voice that could either be live or not, no telling. The guitar playing on this song is so perfect that I would not be surprised if it had studio help, but again there is no way to know unless a live-to-two-track version exists somewhere.
Jeff Norman has said that he kept Garcia’s original “China Cat” vocal on the box set. Although Garcia’s original vocal for “Rider” was also still on tape, Norman used the overdub on that song because of the different harmony phrasing. (The original harmony vocals were most likely erased, while Garcia put his own vocal on a new track.)

Tennessee Jed * This lead vocal was definitely overdubbed, as a different vocal appears on the box set mix.

Greatest Story Ever Told ** This is apparently completely live, with no overdubs.

Jack Straw * This is one of the more interesting vocal overdubs. From its inception until the performance on 5/10/72, all of the verses in “Jack Straw” were sung by Bob Weir. On that date and forevermore after that, Weir and Garcia traded verses in call-and-response fashion. But this version from 5/3/72 has the two singers trading off, so they were obviously overdubbed. Listen very carefully, and I think you will hear the “ghost” (reflections and bleed) of Weir’s voice during Garcia’s verses. This is not obvious on the original album but can be heard on the newer mix. The original live tape of this song has never circulated.
Jeff Norman has said that Weir’s guitar part was also replaced for the album; his new guitar track was put on Pigpen’s empty vocal track. (Norman also mentioned that you can hear Weir’s vocal bleedthrough when Garcia sings.)


May 4, 1972

Deal ** This is apparently completely live, with no overdubs.

Next Time You See Me ** This is apparently completely live, with no overdubs.

Sugar Magnolia * It sounds like there is some doubling of Weir’s vocal (either deliberately or as a remnant of the original vocal bleeding into other mics) and the harmony vocals are almost certainly overdubbed. Donna appears in the coda on this version and was likely overdubbed since this is an anomaly not found on the other live versions from the tour. The overdubbed vocals were used on the box set mix. The original live tape of this song has never circulated.
On the album the Dead included the last ten seconds of “Dark Star” at the start of the song.


May 7, 1972

Dark Star ** This is apparently completely live, with no overdubs.

Drums ** This is apparently completely live, with no overdubs.

The Other One ** This is apparently completely live, with no overdubs. It is of interest to note that while this version did transition to “Sing Me Back Home”, a different version of that song was used on Europe ’72, Volume 2. This is probably because the 5/26/72 version was pulled for possible inclusion on the original album and overdubs were made to it, and the producers decided it was the better of the two versions.


May 10, 1972

He’s Gone * Hearing the 2011 box set mix, it becomes glaringly obvious that the original album version was sped-up and thus pitched about a half-step sharp. The newer mix rectifies this. All the vocals were overdubbed for the album, and the studio vocals were also used on the box set. (Typically, Norman would have used the live vocal if it was salvageable, but here it is likely the overdubbed vocals were recorded over the live vocal tracks. Lemieux has confirmed that the live vocals on the multitrack were erased. The original performance circulates on tape, though.) The backing vocals – not present on this version when it was played live – are included on the box set mix, which is similar to what was done with “Sugar Magnolia” and its coda. In the original live performance, the Dead instrumentally fade out at the end.
Keith’s piano in this song is entirely overdubbed on the album, adding a lot of embellishments. The Dead changed this song the most in the studio, probably because it was the newest song and the early live versions sounded rather primitive.
Blair Jackson wrote in the CD liner notes: “The vocal coda on “He’s Gone” – “Oo-oo-oo, nothin’s gonna bring him back” – was not from the 5/10/72 Amsterdam show that the album version was purportedly drawn from; indeed the coda did not appear on any of the six versions of the song played in Europe. Rather, it was introduced July 16, 1972, at Dillon Stadium in Hartford, Connecticut… But the vocals on the “live” album were added in the studio when Matthews mixed the tapes, long after the Europe tour.” (Blair may not have known when writing this that it would be the overdubbed mix that appeared on the box set. Technically, Norman did not even need to include the studio vocal coda, since it was simply sung over the original instrumental ending.)


May 16, 1972

Beat it on Down the Line ** This is apparently completely live, with no overdubs.


May 23, 1972

Mr. Charlie * This is apparently completely live, with no overdubs.


May 24, 1972

You Win Again * This is apparently completely live, with no overdubs. A lot of reverb was added to the vocal, though, which is true of many of the vocals on the album.

It Hurts Me Too * Keith's piano was definitely overdubbed on the album. His part is much fancier than what he played live. The original live piano was included on the box set mix. The rest of the performance is apparently undubbed.

Playing in the Band ** This is apparently completely live, with no overdubs.


May 26, 1972

Truckin’ * Most of the vocals seem to be live, as very little difference can be heard from the original vocals. However, there are some slight changes – for instance, the “sometimes the light’s all shining on me” bridge at 4:15 is sung more smoothly on the album – so evidently some or all of the vocals were redone. After 5:00, Weir & Garcia’s “get back truckin’ on” vocals were overdubbed on the album, and this new vocal coda was also used on the box set. The original performance had different, shorter ending vocals. (As an aside, this “Truckin’” is rare for the time in not returning to a vocal reprise.)

Epilogue * This is the jam out of “Truckin’” and is apparently completely live. The album track ends at 5:00 with a studio-added reverb effect in Phil’s little solo, just before he starts playing chords in the live performance, snipping out “The Other One.”

Prelude * This is the jam into “Morning Dew” and is apparently completely live.

Morning Dew * The lead vocal was overdubbed for the first two verses, as Garcia sounds hoarse on the box set mix, and not on the album. The live vocal for the rest of the song was left as is. On the album, the end of the song cuts just before the return to “The Other One.”

Sing Me Back Home ** The lead vocal was certainly overdubbed, as there are audible reflections of the original vocal on the box set mix. Also, Donna’s final gospel vocal yell (“come alive”) is only heard as a reflection, unfortunately. My theory is that her original vocal track was overdubbed upon and thus erased, and she did not sing this part during the overdub session. The circulating tape of this show has the original vocals, which are quite different.

Ramble On Rose * This lead vocal was definitely overdubbed, as a different vocal appears on the box set mix. Keith's piano was also overdubbed on the album, and the piano overdub is on the box set mix.

One More Saturday Night * Though it’s almost impossible to tell, Weir redid at least some of his lead vocal – the chorus from 2:20-2:30 is slightly different on the album compared to the box set mix – but in general the vocal inflections are so identical it’s hard to spot any difference, and harder to tell why he took the trouble. Backing vocals were clearly overdubbed at the end, since these were not on the live tape. Pigpen’s organ was omitted from the album, and Keith's piano was overdubbed. The piano overdub is on the box set mix.


Organ Overdubs

There are no organ overdubs on the album.

Although Merl Saunders isn't on the Europe ‘72 credits, a few sources still indicate he was part of the overdubs: McNally's book briefly mentions it, the deaddisc.com discography also lists him on the album, and Merl himself said in an interview, “I played on four or five tracks of Europe ’72.”

But evidently, they were mistaking this album for the Skull and Roses album in 1971, where Saunders did do organ overdubs on several songs. After reviewing all original E72 album mixes, the newer box set mixes of the same takes, and the circulating tapes (plus other takes of the same songs), I see no reason to believe Merl Saunders overdubbed any organ at all.

Pigpen played fine organ parts on the whole tour. He was not flashy, but he was quite reliable and not at all intrusive. There is considerably less organ used in the 1972 album mix than was actually played at the shows. (For instance, the organ was mixed low on “Truckin’,” minimized on “Ramble On Rose,” and omitted on “One More Saturday Night” and “Tennessee Jed.”) In contrast, the 2011 box set keeps the Hammond simmering, presumably any time Pigpen had his hands on it and the volume pedal pushed down. These newer mixes are good in that way. (Often, the piano gets buried, but that is another story for another day.)

There are no Saunders overdubs anywhere to be found. On every song on the original album where some organ is audible, the organ parts on the album are identical to what Pigpen played live, and very similar parts are played by Pigpen on other versions during the tour. There are certainly songs where his organ parts were minimized or completely muted for the original album mixes, but none where a new organ part appears. So the sources stating Merl Saunders was on the Europe ’72 album are clearly wrong! I think it is possible that Saunders simply mis-spoke and was instead remembering his contributions to Skull and Roses.

As far as the other instruments, Keith overdubbed piano on at least several songs - "He's Gone," "It Hurts Me Too," "Ramble On Rose," and "One More Saturday Night." "It Hurts Me Too" is the only one of these where the original live piano was used on the box set mix, which indicates that Keith's live track was usually erased by the overdub. On some performances (mostly the Paris shows) it isn't possible to check since we don't have the undubbed live tapes.

I did not detect any guitar overdubs, but there may be some.


The Sub Reels

The Dead considered more songs for the original album than could be included, along with many candidates for the best performance of each song. One step in the preparation of the album was to select the best tracks from the shows and put them onto sub-reels for final consideration.
David Lemieux explained in one interview: “A lot of the songs were physically cut out from the master reels and put onto another reel for consideration for Europe ’72… They listened to the whole tour, pulled out the best four versions of each song by physically cutting them from the master and putting them on another tape. That was the sub reel of the versions that were being considered for Europe ’72.”
http://www.nodepression.com/profiles/blogs/purely-about-the-music-the
This meant that for the box set, many shows had to be reassembled from the various reels as the songs were put back in their original place.

Lemieux spoke to Blair Jackson about some of the selections on Volume 2: “We ended up including several songs that the band had pulled from the master reels for the original Europe ’72 but which, for whatever reason, didn’t make the cut. That was really the impetus to get this thing rolling—that there was a lot of stuff on the cutting room floor that the band had slated for the original album at some point. Off the top of my head, I can give you three: “Beat It on Down the Line” from Luxembourg [5/16], “Next Time You See Me” from Paris [5/4], and “Sing Me Back Home” from 5/26 [Lyceum]… My guess is that when they made the original album, the big ballad was going to be either the “Morning Dew” or this “Sing Me Back Home.””
http://www.dead.net/features/live/more-europe-%E2%80%9972-vol-2-few-minutes-david-lemieux
As we saw, “Sing Me Back Home” did receive complete vocal redubs for the album before it was put aside. Since the dubbed version was used on the box set, the original vocals may have been erased on the multitrack.

“Two Souls in Communion” from Frankfurt 4/26 had also been selected for possible inclusion on the original album, but ended up as a bonus track on the 2001 CD reissue. Lemieux said: “That song was actually slated for inclusion on Europe ’72. The reason we know that is because everything that was originally going to be included on the album was put onto these sub-reels. That didn’t make it, and Beat It on Down the Line, of all things. Those two songs were going to be included but didn’t make it. On some of the tape boxes it’s called Pig’s Tune and on the rest of them it’s called The Stranger.”
http://www.musicbox-online.com/dl-vault1.html

We see from the tape box images in the hardbound box set book that certain songs were taken from the master reels and spliced to at least nine sub-reels for consideration for inclusion on the album. These include the following:

Mr. Charlie (4/29) – This version was not used. The version from 5/23 was.

China > Rider (4/29) – This version was not used. The version from 5/3 was.

China > Rider (5/3) – This is the version used on the album.

Beat It on Down the Line (5/3) – This version was not used on Volume 2. The version from 5/16 was.

Tennessee Jed (5/3) – This is the version used on the album.

It Hurts Me Too (5/3) – This version was not used. The version from 5/24 was.

Truckin’ (5/3) – This version was not used. The version from 5/26 was.

Jack Straw (5/3) – This is the version used on the album.

Ramble on Rose (5/10) – This version was not used. The version from 5/26 was. There is also a note on this tape box of the second set saying, “This is dynamite,” apparently meaning the whole reel or whole set.

Chinatown Shuffle (5/26) - This version was not used on Volume 2. The version from 4/14 was.

China > Rider (5/26) – This version was not used. The version from 5/3 was.

Sing Me Back Home (5/26) – This version was used on Volume 2. This tape box has a note saying, “We’re all really stoned now.”

One More Saturday Night (5/26) – This is the version used on the album. A note on this tape box says, “The Last God Dawg Gig.”

Unfortunately, we don’t get to see all of the tape boxes. More clues would reside there. The 4/24 tape boxes, seen in the Rockin’ the Rhein release, appear to have no songs selected.

(As an aside, several of the newer songs apparently did not yet have their titles finalized during the tour. The titles used on the tape boxes are “Don’t Expect No Help At All,” “Chuba Chuba,” “He’s Long Gone,” and “Strangers.”) 

Several songs are missing from the circulating tapes of the shows, evidently because they were spliced out of the master reels to put on the sub-reels. These include:

4/8/72 Cumberland Blues
5/3/72 China>Rider, Tennessee Jed, Jack Straw
5/4/72 Sugar Magnolia

On the circulating tapes, these songs are patched from the Europe ’72 album. As a result, we do not have the original live performances to compare to the overdubbed mixes. They may well still exist on two-track copies in the Vault, though. Multiple copies of these shows were made at the time; as Betty Cantor said in an interview with John Dwork, “In Europe I was doing the 16-track and simultaneously running a two-track of my monitor mix. I made cassettes at the same time.” (Deadhead’s Taping Compendium vol. II, p.17)


The Overdub Process

In an interview with Blair Jackson, Bob Matthews explained the decision to redo the vocals on the Europe ’72 live tracks: “The band was almost never happy with their vocals on live recordings. We had overdubbed vocals on ‘Skull and Roses,’ too, but the band was very unhappy about the fact that it sounded like it had been overdubbed. Actually there were some discussions about whether we were even going to do Europe ’72, because of vocal issues, so that’s when I came up with the idea of trying to make [them] sound more live.”
Jackson wrote, “They recreated the positions of [the speakers] with loudspeakers in the big room at Alembic [Studios], set up the singers and their monitors in the same positions they had been onstage, and then played back the instrumental tracks to approximate the actual live performance, as the singers laid down new vocals.”
Matthews said, “Everybody seemed to like that fine. The band wanted the albums to sound as good as they could make them. They weren’t purists at all.” (Grateful Dead Gear, p.119)

These were the track assignments on the Europe ’72 16-tracks:
1. Bass Drum
2. Floor Tom
3. Snare
4. Overhead
5. Hi hat
6. Bass
7. Bass
8. Lead guitar
9. Rhythm guitar
10. Jerry vocal
11. Bob vocal
12. Phil vocal
13. Pig Pen vocal
14. Organ
15. Piano
16. Aud/Sync

There were not many tracks left over if the band decided to overdub vocals in a song. Usually, Pigpen’s vocal track would be empty, and sometimes his organ track, and the band seem to have used those tracks sometimes. But quite often, we see that the original vocal tracks were wiped when recording the new vocals. (On some songs, though, if you listen carefully, you can hear the room echo of the original live vocals under the studio vocals.) The audience track was probably not used for dubs, though it was mixed so low on the album that any audience presence or original room sound is barely detectable. (Plenty of reverb was added to the vocals, though.)

Some live vocals on the multitracks were lost due to the Dead’s method of snipping out the selected tracks from the master tape and recording directly onto them. The original performances survived on Betty Cantor’s two-track tapes, though, many of which leaked out into circulation. These are all apparently still in the Vault. Lemieux said in one interview, “Fortunately, they were running two-track of virtually all the shows to cover any cuts on the multi-track. They were only running one multi-track machine, so if the multi-track did cut in the middle of the song, there was about 20-30 seconds missing of that song, but we do have the two-track recordings that were made simultaneously [so] that we can fix it. We’ve had to do that a couple of times, not too often.”
http://ultimateclassicrock.com/grateful-dead-archivist-david-lemieux-talks-europe-72-box-set/ 
 
Most shows were intact, and some had no songs cut on the multitracks. The Dead were using extra-long 14-inch reels on the tour in order to minimize tapeflips, and the Alembic crew was usually adept at flipping between songs; so hardly any cuts are seen on the available tape boxes. (“Big Boss Man” on 4/7 is one example of a song partly lost because there was no two-track running for that show. This may also be one reason that show never made it into circulation.) The two-tracks were certainly never used for the original album; it is not clear just where two-track tapes were used to patch flips on the box set.

There are just a few cases where tracks are circulating that are missing from the box set: “Casey Jones” at the end of the 4/7 first set, the 4/21 soundcheck of “Loser” and “Black Throated Wind,” and the 5/11 encore of “One More Saturday Night.” (On the other hand, the box set turned up a previously unknown soundcheck on 5/16 of a rare “Big River” and “Sugar Magnolia.”)


Speed Changes

Many of the songs on the album were sped up to varying degrees, and thus are pitched sharp. The box set mixes are pitched correctly. Comparing the song timings allows us to see exactly how much the speed varies from track to track on the album. (Speed changes of more than 1% are noted.)

                               Box Set / Album
Cumberland Blues      5:47 / 5:39  [2.4% fast]
He’s Gone                    6:31 / 6:20  [2.9% fast] *
Saturday Night           4:45 / 4:44
Jack Straw                  4:47 / 4:46
You Win Again           3:53 / 3:53
China > Rider           10:38 / 10:31  [1.1% fast] **
Brown Eyed Women 4:43 / 4:36  [2.5% fast]
Hurts Me Too             7:16 / 7:16
Ramble On Rose        6:07 / 5:59  [2.3% fast]
Sugar Magnolia          7:01 / 6:58
Mr Charlie                   3:39 / 3:36  [1.4% fast]
Tennessee Jed             7:09 / 7:08
Truckin’                       5:06 / 5:01  [1.7% fast] ***
Morning Dew            11:50 / 11:19  [4.5% fast]

* The timing is to the last vocal “he’s gone.” For the full performance, the box set lasts 7:09 and the album 6:54, showing a speed change of 3.6%. (This wider discrepancy in timing is because the box set mix includes a bit more of the performance at the end than the album track, which fades earlier.)
** China > Rider – individual times: box set 5:36+5:02, album 5:32+4:59
*** This timing goes to the last sung line of “get back truckin’ on.” The full timing:
Truckin’ > Epilogue – box set 17:58, album 17:42 [1.5% fast]

Timings are for the song itself, not the length of the CD track, since the album and box set are tracked differently. Some of these timings may be off by a second or so, so the speed percentages may not be exactly precise, but the pattern is clear. Many of the tracks are unchanged, others are sped up almost to chipmunk-vocal levels. The reasons are unknown.


Conclusion

The vast majority of obvious overdubs are found on Jerry Garcia’s lead vocal tracks. Maybe he felt more critical of his performances, or maybe they actually needed the most help because of missed lyrics or other phrasing stumbles. It’s true that his overdubs generally resulted in stronger lead vocals than his live takes. Songs with big vocal harmonies also received bolstering in the studio. Keith also replaced his piano part in several songs with more lively, embellished playing. These live tracks are typically pretty good throughout the tour, but I suppose the temptation to sweeten them was irresistible. On the other end of the scale, Pigpen’s vocals sound entirely live; Lemieux has said that no Pigpen vocals were overdubbed. Of course, he typically delivered very confident lead vocals, even if his pitch was not always spot on. There may also be other reasons why Pigpen was apparently not involved with studio overdubs at all.

Jeff Norman has said that he used the original vocals on the box set where they had not been obliterated on tape by overdubs, and there is no reason to doubt this. However, he did use overdubs on backing vocals where none were sung live, for example on the end of “He’s Gone” and “Sugar Magnolia.” Norman spoke a little about his mixing to David Gans during the box set project: “Wherever there’s an original vocal remaining, I’ll use it.”
http://www.dead.net/features/news/checking-again-europe-72-mixing-engineer-jeffrey-norman

Let’s not forget that big chunks of this tour previously appeared on the archival releases Hundred Year Hall (released in 1995), Steppin’ Out (a compilation of songs recorded on this tour in England, released in 2002), and Rockin’ the Rhein (released in 2004). Also, the box set The Golden Road (released in 2001) and the later individual re-issue of Europe ’72 contained bonus tracks from the tour. Astute listeners will notice that the mixes on these earlier releases is much more refined in terms of dynamics, equalization, reverb, and other sonic niceties than it is on the 2011 box. Keith Godchaux in particular receives more attention to detail on the older mixes. On the 2011 mixes, there is even a distortion issue with the vocals on every show up to the first Paris show (5/3/72) that then pretty much clears up for the rest of the box. Obviously the mixing budget for Europe ’72: The Complete Recordings did not allow for the “extravagance” of the earlier, higher-fidelity mixes.

The only earlier, superior mixes used on the box are Discs 3 and 4 of the 4/24/72 show, previously released as Rockin’ the Rhein. For an unknown reason, these songs were not newly mixed for the box, but the first two discs of this show were. I cannot begin to guess why, except that it saved a few hours of studio time. No other earlier mixes were used anywhere on the box set.

The first song released from this tour was a 24-minute excerpt of “Dark Star” from 4/8, which Garcia and Bob Matthews mixed in a London studio in late May 1972 for the Glastonbury Fayre album. This is one case where we can compare an original Dead mix from the tour with the two recent mixes of that jam, on Steppin’ Out and the box set.
See http://deadessays.blogspot.com/2011/09/dead-glastonbury-fair.html 
For more observations on the box set mix, also see this older discussion:
https://archive.org/post/401638/keith-is-low-in-the-mix

As a final note – I may have missed some overdubs, so please comment if you’ve found anything not mentioned here.