Karl Matthew Alvarez (born March 10, 1964) is an American bassist and songwriter for both the Descendents and All, the band that resulted after the Descendents disbanded again in 1987. Alvarez joined the Descendents after the Enjoy! album from his previous bands The Massacre Guys and Bad Yodelers, and played on all of the All albums, and the Descendents albums All, Everything Sucks, Cool To Be You and Hypercaffium Spazzinate.
