RADIOHEAD “In Rainbows” (www.inrainbows.com) 3 stars A new album by Radiohead is always a big deal, but the way the British art-rock band is releasing “In Rainbows,” its seventh studio effort, is making history. Fans can download the album from www.inrainbows.com. Cost? Your choice. Early results show most fans aren’t greedy moochers, as only about a third have opted for the freebie. Average sale is $8. Radiohead has always been a polarizing musical force.

Many find the group’s experimental noise-rock side cold and impenetrable, and some of it is. But fans cite originality and creative complexity when declaring Radiohead the most important band in the world. “In Rainbows,” by tapping the howl-at-the-moon epic style of 1997’s majestic “OK Computer” and the electronic touches of 2000’s “Kid A,” then adding the bite of raw garage-rock, immediately jumps into the pool for rock album of the year.

Thom Yorke’s unmistakable soaring falsetto, both fragile and a bit twisted, is as strong as ever on the ghostly, elegiac “Nude” and the plaintive “Reckoner,” which recalls the heartbreakingly beautiful nonsense of Icelandic rockers Sigur Ros. There’s also plenty of amped-up muscle: The playfully sloppy garage-rock guitars of “Bodysnatchers” capture T-Rex’s swagger, and the careening, downhill drumming of “Jigsaw Falling Into Place” is balanced by Yorke’s stream-of-consciousness lyrical style.

Yorke’s lyrics largely abandon familiar alienation and nihilism in favor of more straightforward rock themes that tackle actual human relationships. On “Weird Fishes/Arpeggi,” he admits, “I’d be crazy not to follow/Follow where you lead,” before the song evolves into a typically gorgeous cacophony.