DRM impact on artists (Score 2, Insightful)

I wonder what might happen in the future (or the present for that matter) for any artist when users are required to use DRM to play the music produced by that artist. How about if the artist has a unresolved disagreement with the label, and the label, as a way to make the artist conform, summarily disables the ability of any user to play that artist's DRM'ed music? What about old DRM'ed music that the label might consider no longer popular and marketable? Might they allow the "keys" to such music to become no longer available, so that users can no longer play those tunes? The labels are in the business of selling, so they would want music lovers to keep on buying new music rather than listening to old tunes they might have. This also means that a lot of very good, but old, music might become lost because of expiring DRM keys. If DRM had been used in the 1920's, I wonder how much of the great Jazz and Big Band music of that era, and later years, would be perserved today?