On 1976’s A Trick of the Tail, Phil Collins’ vulnerable, earnestly soulful singing gives Genesis’ imposing prog rock the anchor it needed. With its shape-shifting wall of sound, “Dance on a Volcano” is immense but elated, while “Squonk” is a thickset march into the cosmos. Even at their most ambitious, the band display a newfound concentration, and they still relish a bit of fun, especially on the toe-tapping melodies of “A Trick of the Tail” and the gleeful Cockney disco of “Robbery, Assault and Battery.”