... Fuel-Injected Dreams by James Robert Baker ?
Oh my God, yes i read it. My brother bought it for me as a joke birthday present, not actually thinking I would read it...but then I did.
That gave me some weird dreams for a few days.
The descriptions of the "song" (can't remember of the top of my head..."Tidal Wave of Sound"...?) are excellent...made me go back to River Deep Mountain High several times, but the ending, with the revelation, the contents of the bag...dear god, that is twisted.
So, Spector's in jail now, huh?