A Retrospective is the first compilation album by the American group Pink Martini, released in September 2011 in the United Kingdom and the following month in the United States, Australia and Canada. The album contains twenty-one tracks from six studio albums. Guest artists include Michael Feinstein ("How Long Will It Last?"), French singer and songwriter Georges Moustaki ("Ma Solitude") and director Gus Van Sant ("Moon River"); the compilation also features remixes by New York City disc jockey Johnny Dynell ("Una Notte a Napoli") and Hiroshi Wada ("Kikuchiyo to Mohshimasu").