Pearl Jam is an American rock band formed in Seattle, Washington, in 1990. One of the key bands in the grunge movement of the early 1990s, Pearl Jam has outsold and outlasted many of its contemporaries and is considered one of the most influential bands from that decade, dubbed "the most popular American rock and roll band of the '90s". The band has consisted of bassist Jeff Ament, guitarists Stone Gossard and Mike McCready and vocalist/guitarist Eddie Vedder since its formation. Drummers Dave Krusen, Matt Chamberlain, Dave Abbruzzese, Jack Irons and Matt Cameron are former members of the band. Keyboardist Boom Gaspar has also featured with the band as a session and touring musician since 2002.