Well played viv :)
but it was a trick question. It was indeed Edward Van freakin Halen, guitar god and my personal rock idol. But it wasnt eruption....
it was not a particular song. Eddie claims he just laid down a few riffs and its not one i know (and i know em all ;) so that fits
But the tape he slides into his walkman says van halen so your answer is as correct as it can be. I shall make a small donation to the college fund in your name!