Although many of the differences listed herein might seem to be the musings of people with too much spare time, the differences can be very noticeable during listening parties (see Section 2.5) when seemingly small differences in song length can throw off the timing of the party.

Days Of Future Passed was released as a stereo album in 1967. Sometime in the early 1970s a quad mix was released, and was later used to create the dts 5.1 version which was released in 2001. There are some noticeable musical differences, like a lack of backing vocals on "Time to Get Away" and both the abruptness of the beginning of "Dawn is a Feeling" and the reduced reverb used on bridge ("Do you understand, that all over this land...") in the quad/dts mix. Also, in the quad/dts mix the "Overture" gained 25 seconds of previously edited material, and the closing gong is 8 seconds longer. However, the quad/dts mix also cuts 145 seconds from "Peak Hour" and 30 seconds from "Another Morning", compared to the original.
Due to deterioration of the original master stereo tape, a remix was performed in October 1978, and all albums and CDs released after that date, including Mobile Fidelity's, have the remixed version (except for the previously mentioned dts 5.1 release which was created from the quad mix). Although the 1978 remix has some of the characteristics of the quad mix, the quad mix was not simply mixed down to stereo. The "Overture" in 1978 remix is 5 seconds longer than in the quad/dts mix (30 seconds longer than the original); "Dawn is a Feeling" has the same musical differences noted above for the quad/dts mix, but is the same length as the original mix; "Another Morning" is 8 seconds shorter than the original (20 seconds longer than the quad/dts mix); "Peak Hour" is 13 seconds shorter than the quad/dts mix (158 seconds shorter than the original); and the closing gong is the same length as the original.

"Tuesday Afternoon" - Versions on Days Of Future Passed have the bridge ("I'm looking at myself...") with Justin's voice switching to one side of the stereo field, while the version on This is the Moody Blues it was intentionally switched to the other side to give the fans something fresh.

"Nights in White Satin" - There are three mixes - the original mono mix done for the 7" single, a stereo mix without orchestra for the single (also found on Out of This World) and the version on Days Of Future Passed, which is just the stereo mix with orchestra added. Single versions exist at 3:06, 4:20 and 4:26 lengths but are all the same mix. The Moodies also recorded a Spanish-language version, called "Noches de Blanco" (aka "Noches de Seda").

"Ride My See Saw" - On In Search Of the Lost Chord, this song is cross-faded from "Departure." On the single, This is the Moody Blues and Out of This World, the opening drum solo and count-in (the way they perform it live) are audible.

"The Word" - The version on In Search of the Lost Chord is recited over faint mellotron chords, while on This is the Moody Blues it is recited over the instrumental "Beyond" from To Our Children's Children's Children, an intentional change to give fans something fresh.

"Out and In" - The version on the CD Blue on the Pickwick label has a clear intro without the fadeout from "Beyond".

"Lovely to See You" - The version on On the Threshold of a Dream is cross-faded from "In the Beginning" but on Out of This World it appears without the cross-fade. This song was never released as a single, so the origin of this version on Out of This World is a bit of a mystery. Perhaps, like "Floating" (see below), they used the quad tapes and isolated the tracks at the beginning of the song that did not have "In the Beginning" cross-faded over them.

"Floating" - The version on Out of This World has the humming more to the front of the mix than on To Our Children's Children's Children. This song was never released as a single, so the origin of this version on Out of This World is a bit of a mystery. Since the humming is also prominent on the quad mix of the song, perhaps K-Tel used the quad mix and mixed it down to stereo.

"Question" - The version on A Question of Balance has the (Mellotron) orchestra and choir at the beginning. The single version, which also appears on TitMB and OotW, has only guitar. The single version also has Justin's vocals double-tracked and fades out sooner at the end. For The Moody Blues Greatest Hits/Legend of A Band, "Question" was re-recorded with the London Symphony Orchestra.

"Isn't Life Strange" (Seventh Sojourn) - Was re-recorded with the London Symphony Orchestra for The Moody Blues Greatest Hits/Legend of a Band.

On the LP, as well as the CD version of Caught Live +5, there's a lot of material that wasn't included on some of the cassette versions of the album. On "Peak Hour," the cassette edited out Justin's blistering guitar solo and Mike's organ solo in the middle of the song; the disc puts them back in. The cassette version of "Tuesday Afternoon" edits out nearly the entire second half of the song, including the second verse and Ray's flute solo. The LP and CD put them back in. For "Are You Sitting Comfortably?," the LP and CD include a speech by Mike, which introduces the song, and an extra flute solo; neither of which are on cassette. On the LP and CD, "The Voyage" have four extra measures towards the end, which are not on the cassette version. Lastly, the LP and CD versions of "Ride My See Saw" have the guitar a bit louder and clearer, especially during the solo.

"Remember Me, My Friend" (Blue Jays)- The cassette and reel-to-reel tape versions have an extended jam about a minute long at the end.

"Forever Autumn" (War of the Worlds) - There are several versions of this song with Justin Hayward on vocals in addition to the original version by the authors, Paul Vigrass and Gary Osborne (see Section 5.3). The single version featuring Justin Hayward, which was included on the Time Traveller box set and varies in length depending on the media (7" single, 12" single, etc.), didn't have Richard Burton's narration over the song as it was on War of the Worlds. In 1995, War of the Worlds was re-released with two bonus mixes of "Forever Autumn" called "Remix '95" and "Dark Autumn Dub." Other versions of "Forever Autumn" were recorded for Classic Blue and Frankfurt Rock Orchestra - Classic Moody Blues Hits Featuring Justin Hayward and Friends (see below).

"Eve of the War" (War of the Worlds) - There are several versions of this song, as well. In 1978, a single version was released in Europe with lead vocals by Chris Thompson (who sings "Thunderchild" on War of the Worlds) and Justin Hayward on backing harmonies. All other versions, including those on the album, have Justin on lead vocals. Both single versions, backed with "The Red Weed", and the first War of the Worlds CD (all released in 1989) have the bass mixed further back than on the LP. As mentioned with "Forever Autumn," a new mix of this song called "pr²h mix" appeared along with the original version on the 1995 CD release of War of the Worlds. The name of the remix represents the formula for the volume of a cylinder, which was the shape of the Martian ships (the Greek letter p times the radius, r, squared; times the height, h).

"Thunderchild" (War of the Worlds) - The version on the original release had lead vocals by Chris Thompson, but apparently John Lodge also was considered. The "Collector's Edition" of War of the Worlds, released in 2005 included many previously un-released tracks, including the John Lodge version of "Thunderchild". The booklet accompanying the "Collector's Edition" says that the Lodge version was never completed because he "had touring commitments with his band".

"Survival" (Octave) - There is an extra 1:15 of music at the end of the New York-manufactured CD (which all new copies are) that was not on the US LP or the original CD release manufactured in Hanover, West Germany. It has great group vocals and killer guitar from Justin to the fadeout.

"Veteran Cosmic Rocker" (Long Distance Voyager) - The CD, cassette and American-pressed version of the LP have "backward talking" at the end of the song (see Section 5.17), while the Japanese-pressed LP does not. On the LPs, the sitar fades out at the end but, on the CD, the sitar is double-tracked with a reversed sitar.

"Sitting at the Wheel" (The Present) - PolyGram's office in Germany took it upon itself to hire a remix engineer, redo the song and release it as a 12-inch single when The Present came out. The remixed "Sitting at the Wheel" was released only as a 12-inch single in 1983 and, then, only in Germany. It's now available in Europe on The Moody Blues Master Series, which was released in 1998. The 7-minute remix is nifty because it uses all the original tracks (and only the originals) from the song. The remix engineer just broke down the song into its discrete parts and rebuilt it, by isolating them and combining them in different ways. Some of the revelations include an excellent acoustic guitar part (strumming), that's virtually inaudible on the album mix, and the entire ripping slide-guitar solo. The only real liberty the engineer took was adding some echo to John vocals. It's really a top-notch effort.

Moving Mountains was released on the Towerbell and Anchor labels in various forms (see Section 3.2) with totally different running orders. The versions of "Is It Just a Game?" and "Silverbird" are also different. The Anchor version of "Is It Just a Game?" adds two lines to the end of each of the first two verses ("Does it all come down to what we've done before?/Is it truth and love that we're searching for?" and "Does it all come down to what we've done before?/Is it peace and love that we're searching for?," respectively). "Silverbird" is about 1:47 longer on the Anchor version with extended instrumentals for the intro and in the break before, "When I close my eyes, I see you there;" an extra chorus ("So fly, my silverbird...") before the guitar solo; and a longer outro (10 repetitions of "Oh, oh, oh my silverbird, come on home to stay," instead of 7 on the Towerbell versions.)

"I Know You're Out There Somewhere" (Sur La Mer) - The Moodies also recorded a Spanish-language version, called "Al Fin Voy A EnContrarte " in 1988.

"Bless the Wings (That Bring You Back)" (Keys of the Kingdom) - There are three versions of this song. The CD single had orchestration by Anne Dudley (who went on to win an Academy Award in 1998 for her work on the movie, "The Full Monty"), which is different from the Red Rocks orchestration done by Larry Baird. The version on Keys of the Kingdom has no orchestration.

On Frankfurt Rock Orchestra - Classic Moody Blues Hits Featuring Justin Hayward and Friends (released under many titles, see Section 3.2), Justin does different versions of "Forever Autumn," "Running Water," "Blue World," "Blue Guitar," "Voices in the Sky" and "In My World."