William Frank Szymczyk is an American music producer and recording engineer best known for working with rock and blues musicians, most notably the Eagles in the 1970s. He produced many top albums and singles of the 1970s, though—aside from continuing to work with Joe Walsh—he retired from the music business in 1990. He re-emerged in the late 2000s, taking on select projects including the 2007 Eagles album Long Road Out of Eden and the 2008 eponymous debut of Brian Vander Ark.