In 1973, inspired by George Crumb's 1970 Vietnam protest piece "Black Angels," draft dodger David Harrington returned from Canada and founded Kronos Quartet, dedicating it to the exploration of music by such new composers as Crumb and Terry Riley. Though the group (which also includes John Sherba, Hank Dutt, and Joan Jeanrenaud) became notorious for its propensity to dress like pop stars and play Jimi Hendrix covers, Kronos Quartet will perhaps always be best known for raising awareness of many otherwise unknown or generally inaccessible composers. Twentieth-century classical music, with its frequent detours into atonality and minimalism, sometimes proves daunting for newcomers used to the usual Mozart, Bach, and Beethoven; but, thanks to its immense talents, Kronos Quartet discovered an audience for some of this century's headiest music. The band has commissioned more than 400 works from dozens of new composers, from John Adams to John Zorn, and at the tail end of its 25th anniversary, Kronos Quartet's longtime label has collected some of its most memorable and historic works for a massive 10-disc retrospective. 25 Years features works by favorites Adams, Philip Glass, Steve Reich (whose work warranted his own 10-disc collection last year), Arvo Part, and Henryk Gorecki—some of the most popular composers with whom Kronos has worked—as well as key pieces by Crumb, Riley, and Morton Feldman, whose 80-minute "Piano And String Quartet" is a dreamy, yet methodical, highlight. Most of this material has been released before, though 25 Years boasts several re-recordings and a handful of new pieces—including a recording of the first work Kronos Quartet ever commissioned, Ken Benshoof's "Traveling Music," which Harrington paid for with doughnuts. Ultimately, much of this material will already be familiar to Kronos Quartet fans, and neophytes might want to consider one of the group's many excellent albums as an alternative to this box. But that doesn't necessarily mean you'll want to pass it up: While 25 Years ignores the Hendrix novelties in favor of the Quartet's more somber fare, the move actually focuses the impact of the sometimes too-smart-for-its-own-good outfit. It's amazing to hear this many great pieces in the boxed context of a career-capper like 25 Years.