Conventional rock-crit wisdom tends to state that the Stones were completely out of their depth when it came to psychedelia. But while it’s probably an easier stance to take if you swear by the astounding four-studio-album run they subsequently started with Beggars Banquet, Their Satanic Majesties Request isn’t so much a fiasco as it is a fascinating detour — one that fulfilled the promise of some of Between the Buttons’ more baroque moments and threw in some shaggy cosmic-dirtbag jam sessions for kicks. The deeper delves into the lysergic are good swan songs for Mick Jagger in boyish-wonder mode — he’d rarely sound as awestruck again as he does on the summery “She’s A Rainbow” or the Floyd-rivalling Brian Jones Mellotron astrologue “2000 Light Years From Home” — though his more characteristically louche snarling is more than welcome on the alternately grimy and rollicking modern-medieval freakout “Citadel.” There’s also more than enough evidence on this album alone that Keith Richards could get just plain weird when he wanted to — get a load of both his suspense-flick guitar filigree on the intro of “2000 Light Years From Home,” and the overloaded demi-funk riff that serves as its de facto solo. On top of all that, the ramshackle bummer-folk futurism of “2000 Man” is one of the few things that can truly unite Wes Anderson (Bottle Rocket) and KISS (Dynasty), while the electro-acoustic folk blues of “The Lantern” sounds like a coming-down dry run for the more spent, dazed, and heartsick numbers that would make their ’68-’72 run so indelible.