Our school recently tore down its theater and built a new one.
Just before the old one was torn down, i went in and raided the shelves behind the sound equipment. There were several boxes of really old vinyl records and reel-to-reel tapes back there, and i grabbed all the vinyl i could get my hands on.
There were some really trippy finds in there-- the records hadn't been touched since the seventies, practically. It was mostly folk but there were a couple times i got really lucky and stumbled across some early, really weird electronic music.
But the greatest find of all in the entire bunch was this one record i came across, labelled as being put out by "CBS labs", of diagnostic music. Although calling it "music" may be misleading. The intention was that people could use the record to test their sound systems.. it's really odd stuff, mostly test tones and such.
The nifty thing was that because it would have long sections of repetitive, simplistic elements-- i.e. one tone of constant volume getting progressively higher in pitch over several minutes-- certain areas of the record's surface have an actual, repetitive, organic texture caused by the waves within the groove getting closer and closer together as the groove gets closer to the center.
I want so badly to try doing some scratching with this thing, but i'm deathly afraid of damaging it so i haven't yet. I may try after i've made a copy and gotten a slipmat (which i haven't gotten around to getting yet as i'm using the turntable primarily for actually, um, y'know, listening to the records.. and also because i'm a lazy bastard. Not that i haven't been playing with scratching, of course.. -_-).