spectrum is the debut solo album by jazz fusion drummer Billy Cobham. The album was heavily influenced by the music of Miles Davis, with whom Cobham had previously collaborated extensively, and Cobham's previous band Mahavishnu Orchestra.
The song "Stratus" appears in the video game Grand Theft Auto IV of the radio station "Fusion FM", as well as being the main sample in the Massive Attack hit "Safe from Harm".
Ken Scott, engineer of Spectrum, recounted: "Bill Cobham's drums were treated in exactly the same way as I recorded every other drummer. I just used more mics: Neumann U67s on toms, D20s or RE20s (at Electric Lady) on the bass drums, Neumann KM54 or 56 on snare, and either STC 4038s or Beyer M160 ribbon mics for the overheads. One other thing: in order to dampen the snare, Bill just laid his wallet on the top head."
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."
Tommy Bolin, who joined the hard rock band Deep Purple two years later, plays lead guitar on four songs. Cobham had met Bolin years before, when he was a member of Zephyr.
"To the Women in My Life" is unusual in that Cobham himself does not play on it, though he did produce the track. It is an unaccompanied piano piece performed by Jan Hammer.
All songs written and composed by Billy Cobham.
"Quadrant 4" – 4:20
"Searching for the Right Door" – 1:19 / "Spectrum" – 5:07
"Anxiety" – 1:41 / "Taurian Matador" – 3:03
"Stratus" – 9:48
"To the Women in My Life" – 0:51 / "Le Lis" – 3:20
"Snoopy's Search" – 1:02 / "Red Baron" – 6:37
Though tracks 2, 3, 5, and 6 are designated as medleys, all of the component songs have clean breaks between them.