Permanent Waves

There’s an elvish spirit at play in Rush’s cascading prog rock. “Freewill” has a gleeful off-kilter skip, and the evergreen “Spirit of Radio” seethes with joyful ideas, from the much-sampled guitar twiddles to the reggae ‘n’ riffs latter sections. Their strident dynamics are lethally sharp, but poppy on “Jacob’s Ladder”, while Geddy Lee’s voice takes on a lower, more gnomish tone (“Entre Nous”) that even verges on outright eerie in the opening movements of the blistering epic “Natural Science”.