From Zappa Wiki Jawaka
Eugene Chadbourne (January 4, 1954) is a Canadian avant garde jazz and rock singer, guitarist and banjoist.
Chadbourne is a huge Zappa fan and even recorded a song called "Zappa medley", which he frequently performs during concerts and cites several well known Zappa songs like "Let's Make The Water Turn Black". Together with Jimmy Carl Black he formed the group "The Jack and Jim Show", who also performed on a few Zappa tribute shows.
Zappa was asked in the Ode To Gravity - Frank Zappa: World Affairs Commentator interview if he had ever heard Chadbourne's "Zappa medley", but he didn't.