You can debate forever whether copying music is thievery (it likely is). But for the same reason that no one tries to tax the air you breathe, it will be impossible to effectively tax or price digital music because it's value is as close to zero as you can get.
You buy a record (CD, tape, whatever), You get the right to play as many cuts as you want as many times as you like. You get the right to loan it to a friend, neighbor (a library gets the right to loan it out to almost anybody).
You could break the record up so just one track is in each piece and loan those out. They could be played on a turntable. You could design a CD player to do the same thing. You could put ten tone arms on a turntable and play each cut at the same time.
The point being that as long as only one instance of the same is being played at a time, it's legal - in perpetuity! Enter technology to make sharing MUCH easier. Legal point doesn't change. You should be able to copy your record (CD etc., whatever) to your computer and stream it to anyONE (person) for non comercial benefit.
Taken a step further, as long as there are fewer instances of a song playing in the universe at any one time than there were "hard" copies (licenses) sold, there's no beef. That pretty much takes care of songs issued before say, 1995.
For the newer stuff? I'll get back to ya, but I'm sure there's some way to give the RIAA what is has coming.