Mark Avsec (born August 23, 1954) is an American rock keyboardist / songwriter / producer, and more recently (since 1995) copyright lawyer, who is best known for being a member of Donnie Iris & the Cruisers since 1979. Avsec co-founded this band, wrote or co-wrote all of the band's music, was its sole lyricist, and produced all of its albums.