Mono-lithic
A customer wrote to a record company and sent me a drop copy, which I reproduce herein:
I recently bought the subject cd and found that many of the tracks were in mono. many of these mono tracks were played on the radio in stereo. can you explain why in this high tech age these tracks are in mono instead of stereo? I would have preferred to hear this in stereo as much as possible. I understand that recordings originally done in mono can not be made into stereo, but what of those that I’ve heard on radio in stereo?
I should point out here that the “subject cd” was a compilation by the Beach Boys, much of whose recorded oeuvre was released in mono or in (gag) “Duophonic” phonus-bolognus simulated stereo — because, we are reminded, Brian Wilson was deaf in one ear and mixed this stuff to mono because that’s all he could hear.
In the 1990s, for whatever reason, the group, or Brian himself, relented, and allowed some of these tracks to be remixed into stereo. The obvious place to begin was Pet Sounds, and a yummy box set was issued with both mono and remixed stereo versions, plus bits and pieces from the stage tapes. It was successful enough, decided Capitol, to allow further expeditions into the vaults, and the results have been generally successful — because they have the session tapes and therefore the capacity to remix them into proper stereo.
The operative word here is “proper,” keeping in mind that a good mono mix is always to be preferred to a bad stereo mix. I wrote about this at length some years ago and cited some examples of the latter. (Among the worst stereo mixes extant is the overechoed, ping-pongy “I Love You” by People — on Capitol, by coincidence — which becomes unlistenable long before the 4:35 running time is over.)
Still, if Capitol does have fresh new Beach Boys mixes available, why don’t they use them on all Beach Boys product? The answer, of course, can be found at the cash register: the number of people who can be sold any old Beach Boys compilation is far greater than the number of people who insist on hearing “Heroes and Villains” in stereo for once. And they’re not going to go back and remaster a CD that sold well just to punch in new tracks that Joe and Susan Sixpack may not recognize as new.
As for myself, I have accumulated a fair amount of uncommon (if not always “rare”) stereo, and I use it on my personal compilations most of the time, though there are reasons why I might not. Often it’s a question of length: staying with the Beach Boys for the moment, the stereo mix of “Fun, Fun, Fun” fades out almost 20 seconds earlier than the mono 45 version. And sometimes the stereo mix just rubs me the wrong way: Capitol redid the Outsiders (the US band) material for a compilation, and the vintage mixes, despite dubious placement — the lead vocal on “Time Won’t Let Me” falls hard left — somehow sounded more forceful than the more-conventionally-placed remix.
That said, though, I still get something of a kick when I hear something in stereo that I never thought I would. And to that extent, I have to sympathize with my (once-removed) correspondent.

Track listing for 111118-2:
Track listing for 111117-2: