One of the problems with looking at historical trends in recording sales is that such sales are driven to a significant degree by technological change. Over the 100 or so years since the first recording of an orchestra was made, there have been constant improvement in the technologies for both producing recordings and playing them back. But only a handful of such improvements appeared to have caused a real upswing in the volume of recordings sold. Trying to analyze trends in recording sales over long periods of time without factoring in the impact of such dislocating technologies can lead to a distorted picture of the underlying demand for classical recording and what drives it.
Looking backwards, it is clear that the switch from vinyl LPs to CDs was the impetus to produce a great many new recordings, although the switch from analog to digital mastering, which happened around the same time, was a factor as well, in that recordings made using digital technologies were perceived as “better” than recordings made with analog tape.
I suspect that the transition from mono to stereo recording in the late 50s also motivated record companies to re-record much of their catalogs, as clearly stereo sound had the potential to be more “life-like” than did mono. And it seems likely that the switch from 78s to LPs also resulted in lots of new recordings, especially as other improvements in the mastering process made new recordings sound better than simply re-releasing old 78s in the new LP format.
The common element in these technological discontinuities, and what motivated consumers to demand new recordings in the new formats, were that the new technologies were both more convenient and perceived as sounding better. It’s also worth noting that these discontinuities, and the resulting sales boosts, occurred at 10- to 20-year intervals, providing plenty of time for the industry to produce a new catalog of recordings of all the major repertoire (and much of the minor repertoire as well) without huge gaps between the resulting sales surges.
So we’re due for another one, right? One real problem for the classical sliver of the recording industry is that a new technology that combines both convenience and better sound is nowhere on the horizon. Downloads are arguably more convenient - at least for some people - but downloaded recordings generally sound no better, and often somewhat worse, than CDs. Those technological improvements that were touted as providing better sound - SACD and DVD-Audio - apparently weren’t enough better than anyone but audio geeks were interested. Surround-sound recordings certainly have the potential to sound better than conventional stereo, but the market for them too remains at niche levels.
So a major driver of new recording sales is AWOL when we most need it.