For me it was "House of the Rising Sun" by the Animals, the arpeggios . Would have been in the late 60's I guess, 68 or 69.

When I first started playing lead guitar a couple of years later there were no books, tablature hadn't been invented yet as far as I know.
I had a reel to reel tape recorder, I used to tape the song at 7 1/2 then play it back at 3 3/4 to figure out the harder lead parts. Speed was slowed by half, but of course it also dropped an octave in pitch.

Fun times!