Isotope, 1974

I suppose Isotope is technically Gary Boyle's band, but I know of them—and have this particular record—since it's one of the many projects Hugh Hopper flitted through after he left Soft Machine. Illusion lives solidly at the fusion end of the progressive rock spectrum. It's not genteel though. Sure, they've got all the hairpin tempo and time signature shifts you would expect as well as stylistic nods—from jazz to flamenco to funk—but it's the snarling interplay of Hopper and keyboardist Laurence Scott that really draws. For the nearly the entire record, they're molding jointed distorted forms together in ways that (in a different setting) would sound amazingly current.