Leland Sklar, bassist on four of the songs, remarked, "Spectrum is such a benchmark for so many people. There was a sort of fire in it. It was new ground and it wasn't very analytical. It was more flying by the seat of your pants. That's where great accidents happen, which seems impossible these days. We never did more than a couple of takes on any of it. It was more or less a two-day record. It went by so fast." Sklar and Hammer recall that the music was recorded live and was not fixed in any way afterwards, which, in particular, resulted in capturing Tommy Bolin breaking his high E string while soloing on "Taurian Matador" (approximately at 1:45 into the track) and continuing playing. Bolin used Fender Stratocaster and Maestro Echoplex delay unit, prominently heard on "Quadrant 4". Sklar attests that he played his 1962 Fender Jazz bass through a small Univox amp with a single 12″ speaker.