Obviously I haven't had a chance to listen to all of it yet. The first thing I put on was the mono Sgt. Pepper, which I'd never heard. Wow. It really is a different and better album in mono.
Let's back up for a moment. Why mono? When the Beatles first began, only audiophiles had stereo equipment and the music usually released in stereo was for that audience -- classical and jazz. Pop music was played on record players. Not turntables, not stereos, but record players, like the kind we had at home when I was young, with a cover that latched down and a handle so you could lug it to your friends' house. And it was broadcast on AM radio. All of which were monaural, meaning, just one channel. No left and right channels like we're all used to in our headphones. I listened to most pop music in mono, on a cassette player, on my little red-ball AM radio, until I was in high school.
The Beatles, mindful of their audience, released all their music in both stereo and mono mixes for their entire careers. And for two-thirds of that period, the mono mix was the more important of the two. That was the one they supervised personally, and listened to when they were deciding what to release. Stereo mixes were usually done later, sometimes years later, by staff engineers, perhaps overseen by George Martin. It wasn't until the very last of their albums that they worked primarily on the stereo mix, with a mono mix being created by "folding down" the stereo mix, centering both channels. The original mono mixes were not created like that; the albums were specifically mixed for mono, and then stereo versions were created later from the master tapes.
Have you ever noticed that "I'm Looking Through You" has a false start sometimes, and sometimes doesn't? The stereo mix had the false start and the mono mix didn't. Have you ever noticed the moment in "If I Fell" where Paul's voice breaks badly trying to hit a harmony note? That's only on the stereo mix.
Sgt. Pepper in mono is quite different. A number of the songs are faster in mono than they were in stereo. Some songs are longer or shorter, and the emphasis changes for some of them. "Good Morning, Good Morning," one of my favorite obscure Beatles songs, really caught my attention. The kickoff is crisper, the brass and guitar are much higher in the mix, and in general it's a hotter song. Overall, it's a better album and I can now understand the disappointment of people who replaced their original mono copy of the album with a stereo version.
I've also listened to the "Mono Masters," the singles and other songs that never appeared on the original UK albums. Some of them are magnificent -- "Paperback Writer" in particular. The guitars punch and the bass (pushed higher in the mixing and mastering over the objections of conservative EMI engineers after the Beatles demanded to know why the bass sounded so much better on American pop records) really drives the song.
I'm listening to the White Album right now and I hear all sorts of things -- different instrumental fills, different solos, changes in endings, etc. These differences are subtle; many would probably be unnoticeable to most listeners. But I spent a lot of time listening to Beatles music, at a very impressionable age, and I know every damn note of these songs, and they're surprisingly different. And better.
Some of this may also be due to the remastering process; I'll be very interested to compare these albums to the stereo box that I hope will arrive on Monday. And I should also say, to all the purists, that I don't think the mono versions of their early albums will ever eclipse the U.S. stereo versions that I grew up with (which, as Bruce Spizer points out in this excellent essay, are not nearly as bad as some critics like to say), which were released a few years ago on the Capitol Boxes (which I wrote about at length when I got them a few years ago).
(Side note: I was wildy amused to see that J&R quoted a post I wrote a little while ago about how much I like to buy albums there. I wonder if they'll delete the comment I just made, linking to my post from Wednesday about my attempt to buy the Beatles boxes.)