Spirit’s last album is also their magnum opus. Helmed by Neil Young producer David Briggs (who brings a real sonic gravitas to the songs), it hints of environmental catastrophes (the magnificent “Nature’s Way”) and hallucinogenic dreaming (the jazzy “Space Child”). But the loose concepts here are really psychedelic treatises; the album reveals Spirit to be lunatics who brought some sweet mojo to the party. The beautifully optimistic “Life Has Just Begun,” the David Crosby–gentle “Soldier,” and the towering “Morning Will Come” (oh those horns!) all adhere to late-’60s, early-’70s musical transcendence, when rock ’n’ roll landscapes were still wide open.