Volume 1 of the Music of League of Legends, a collection of 15 "new and classic" tracks from the game, is now available for purchase from iTunes, Google Play, and other fine online retailers. Or, if you prefer, you can just download it for free directly from Riot.
The tracks are in MP3 format, perhaps disappointing for die-hard audiophiles, but they're 320kbps, which is about as good as it gets. Each track can also be played individually on the LoL site, if you want to try before you buy—although "buy," remember, in this case means "download at no charge."
I haven't listened to all of the tracks yet, but what I've heard so far is really good, sometimes brooding, sometimes bombastic, and in the case of The Curse of the Sad Mummy, kind of... well, sad, too. But as good as it is, the real treat for fans of videogame music may actually be Frequencies, a 46-minute documentary that takes a behind-the-scenes look at the creation of the soundtrack.
"Music and games share an intertwined history stretching back to neon-soaked arcades and dusty living rooms crowded with tangles of twisting plastic controller cords. From chiptune scores to the sweeping symphonies of expansive fantasy worlds,the relationship shared between games and music simultaneously elevates both art forms," the Frequencies site says. "Frequencies is a behind-the-scenes look at that harmony at Riot; the moment when creativity, collaboration, and passion collide to forge and reinforce story through music."
As far as I can tell there's no time limit on the freebie, but the fact that it's being offered for sale—as in, not for free—on other sites makes me think that there may be a clock ticking away somewhere. Best grab it while you can.