Wirtz (born 3 September 1943 in Strasbourg, France) is an Alsatian pop music record producer, composer, singer, musician, author, and comedian.
As a producer, Wirtz's most famous output is from the mid to late 1960s, when he worked at Abbey Road Studios with Beatles engineer Geoff Emerick, under contract to EMI.
Wirtz is chiefly known for the never-completed A Teenage Opera concept album.
Another track by Wirtz, the 1966 "A Touch of Velvet, A Sting of Brass" under the name Mood Mosaic, with The Ladybirds as backing singers, became well known in Germany as the theme tune for the Radio Bremen show Musikladen and was used by some radio stations and DJs in the United Kingdom as ident, notably Dave Lee Travis on Radio Caroline.
His signature style has been described by Mojo magazine as "Phil Spector scoring Camberwick Green", a sound most perfectly encapsulated on Wirtz's 1967 hit single "Grocer Jack (Excerpt from A Teenage Opera)".