I always try to post comments also as a main entry, just in case you don't read all the comments.
I am not sure if i published this one so to make sure here it is:
Blogger John Shultz said...
The music I have heard in the intros of the early seventies airchecks is from Jimi Hendrix's tune "If 6 Was 9" from his "Axis: Bold as Love" album from 1967. It was also used in the soundtrack for "Easy Rider". The intro excerpted from the middle of the piece, where Hendrix was using feedback from his amp to create a psuedo-melodic electronic warbling that is unmistakably psychedelic. A perfect choice.