The Beatles In Mono Remastered Box Set features The Beatles first 10 albums in their original mono along with the “Mono Masters” double CD compilation which includes the original mono mixes for all of their non-album songs that were mixed in mono.
The Beatles Mono CD Box Set is a real “revelation” in some cases. A lot of the band’s earlier songs really sound a lot~better in mono than they do in stereo because they were originally mixed in mono and the stereo mixes were often done as an “afterthought” (because stereo wasn’t taken very seriously at the time.) Many of The Beatles stereo mixes are totally “wrong” by the standards of today because they pan everything to one side or the other which can be unsettling to listen to (particularly when listening on headphones.)
It’s good to be able to hear songs like “Taxman” & “Eleanor Rigby” without the wide panning that mars their stereo mixes.
But there’s more differences to these mono mixes than just the panning. In quite a few cases there are actually different takes and different effects used! And in many more cases different instruments/parts are highlighted in the mono mix vs. the stereo mix.
A great example of a different mix in mono vs. stereo is “Helter Skelter” because it’s almost a full minute shorter in mono than in stereo and it doesn’t include the “blisters on my fingers” yell at the end.
Another good example is all of the extra vocal effects on the mono version of “Lucy in the Sky with Diamonds.” But really a lot of the songs on the mono Pepper have a lot more vocal effects than do their stereo brothers.
Perhaps the most interesting thing about the Beatles Mono Masters Compilation is that it includes four previously unreleased mono mixes (“All Together Now,” “Hey Bulldog,” “Only a Northern Song and “It’s All Too Much.”) These four songs were never released in mono (in any format) before because when the Yellow Submarine album was first released in ’69 it was only released in stereo (which is why the entire album is not included in the mono box, the George Martin instrumentals were never mixed in mono) so these mono mixes were shelved in Abbey Road Studios for 40 years before finally being heard in 2009.