"Eruption" was played on the Frankenstrat, with an MXR Phase 90, an Echoplex, a Univox echo unit and a 1968 Marshall 1959 Super Lead tube amp.
[2] The piece that would later be named "Eruption" had existed as part of Van Halen's stage act at least as far back as 1975, when it featured no tapping.
Initially, "Eruption" was not considered as a track for the Van Halen album as it was just a guitar solo Eddie performed live in the clubs.
'"[8] "Spanish Fly", an acoustic guitar solo on Van Halen II, can be viewed as a nylon-string version of "Eruption", expanding on similar techniques.
Similarly, it was suggested by Templeman for inclusion on the album after he heard Eddie Van Halen playing a classical guitar.