The Red Hot organization has been putting out charity compilations each year for the past 20, back when such things were more often referred to as “mix tapes.” They’ve had some good scores, including Red Hot + Blue, a collection of Cole Porter tunes covered by ’80s bands, and No Alternative, a virtual yearbook of the best bands of 1994 — Nirvana, Pavement, Soundgarden, Sonic Youth. This year’s contribution, Dark Was the Night, equals and may even surpass both of those; it’s a virtual primer to the best indie rock bands working today. This is hardly accidental. The compilation (available as two CDs, digital download, or a splendid triple-vinyl edition) was produced by brothers Bryce and Aaron Dressner, better known as the rhythm section of the National. Spoon, the Decemberists, Bon Iver, and Yo la Tengo all contributed originals as good as anything on their own records. But the fun in compilations is watching artists at play, and at times the collection recalls those childhood games that let you swap, say, the head of a firefighter with the boots of a dragon: Antony Hegarty’s quavering soprano is accompanied by Bryce Dressner’s acoustic guitar (which usually backs Matt Berninger’s baritone) on a Dylan cover; Feist pairs up with Grizzly Bear (who contributes a separate song) and also covers a Vashti Bunyan song with Deathcab for Cutie’s Ben Gibbard; Blonde Redhead (an American band consisting of a Japanese-born vocalist and a pair of Italian-born twin brothers) teams up with Australia’s Devastations. The covers on the record have a certain wit: Dave Sitek of TV on the Radio does a bang-up job with the Troggs’ “With a Girl Like You” and the New Pornographers cover “Hey, Snow White” by Destroyer, the name used by band member Dan Bejar when he isn’t letting anyone else mess with his music.