In its 23 years of existence, nobody has managed to adequately explain why the Rock and Roll Hall of Fame needs to exist. Apparently it's necessary for an entire generation's self-esteem that a museum in Cleveland anoint some arbitrary crew of rock stars every year. Well, the Hall of Fame just announced its 2009 inductions, so here we go again. (Via Rolling Stone.)Run-DMC and Metallica are probably the two most interesting inclusions in this year's list of Hall of Fame inductees. Run-DMC is the second rap group in the Hall, following Grandmaster Flash and the Furious Five a couple of years ago, and Metallica is one of the Hall's first metal bands-- the exact number depending on how exactly you choose to define "metal." This year's class also includes baby-boomer guitar hero Jeff Beck, soul great Bobby Womack, doo-wop group Little Anthony and the Imperials, and early rockabilly star Wanda Jackson. There's also a sideman category, and this year Elvis bassist Bill Black and drummer D.J. Fontana and longtime session pianist Dewey Lyndon "Spooner" Oldham get the nod.As ever, it's more interesting to contemplate who didn't make it in than who did. Every year, the Hall picks a bunch of artists to nominate and then lets most of them in. This year, the Stooges were nominated for like the umpteenth millionth time, but they were cut again, even after paying tribute to Madonna at last year's induction ceremony. Another near-indefensible exclusion is Chic, the group responsible for like half the really great disco songs ever, and this also isn't the first time the Hall passed them over. Apparently it was so urgent and necessary to throw Jeff Beck a bone (even though Beck's already in the Hall as a member of the Yardbirds) that the Stooges and Chic just didn't make the cut. Latin funk pioneers War also failed make the final cut.The induction ceremony will go down at the Cleveland museum on April 4, and Fuse will broadcast it. Run-DMC will perform for the first time since Jam Master Jay's 2002 murder.