Ruth Underwood is an American musician who is best known for playing xylophone, marimba, vibraphone, and other percussion instruments in Frank Zappa and the Mothers of Invention [1]. She was an integral part of Frank Zappa's band and stayed mostly in the background on stage and in the studio, filling the sound with her indispensable contributions on marimba, harp, xylophone, vibraphone, and drums [2]. Underwood was professionally trained at Ithaca College and Juilliard in the classical tradition, studying both timpani and percussion [1]. She collaborated with the Mothers of Invention from 1968 to 1977 [1].

Underwood's drum work is more than effective in giving the music a very unique sound [3]. She is a classically trained percussionist and has played a variety of instruments throughout her career, including marimba, synthesizer, vibraphone, and drums [6]. Underwood's reputation is unmistakably that of an icon, as revered among the present generation of percussionists as Jimi Hendrix or Poison Ivy Rorschach are among guitarists [2].

Underwood's discography includes her work with Frank Zappa and the Mothers of Invention, as well as her solo work [4]. She has also volunteered as a music teacher for underprivileged students [2]. Underwood's career was mostly dedicated to Frank Zappa's band from 1969 to 1982 [4]. She married fellow Zappa musician Ian Underwood in May 1969 [4].