I guess it's a cost issue: taking the gear along to the concert hall for the regular-program event even several nights in a row is a lot cheaper than renting the studio or that church and everything else for the time you'd need. But I agree with the point that it's becoming a bit dubious with this practice; as the technical possibilities increase anything will soon be possible. Even splicing is no longer audible, really. What'll happen to the idea of the "artist" for example? Is the artist the perfect performer who's "put together" from bits and pieces for the CD we then buy, or the one sweating on the concert stage with all those errors, hesitations, and waverings both visible and audible?
In other words, this all touches the issue of "authorship" too. This by the way was most interestingly broached by the "Joyce Hatto" scandal: the recordings by real, living artists got snubbed, going unnoticed until Hatto's husband using his computer copied the discs and tampered with their speed, making the performance faster or slower by a second or two and then selling the record under his wife's name. After that, the "critics" went screaming that a genius had been discovered. So who's the author/artist, in this case, if the music wasn't good enough before, until the speed was altered by that crucial one second apparently making all the difference in the world -- the original artist playing on the tape, or Hatto's husband who gave it the "final touch" that made it, finally, Great Art...? The latter was apparently a genius, then,
and hence the real artist deserving the credit -- right? Through his seemingly small creative input he made a masterpiece out of the ho-hum. This issue about authorship [and copyright ownership] will only become more and more burning as we go along.
So your questions always point to an underlying dilemma: What is music, then -- the stuff we hear on records or the thing they did on stage the other night?
I'm not sure myself, and the score, too, enters the equation, but for the live feel I simply go for the Sixties' jazz. (The recordings came out pretty well technically by then and there was a lot of that much-missed enthusiasm in the air still.)
-PT