Heinz Kiessling (March 11, 1926 – December 27, 2003) was a German musician, conductor, composer and music producer, known mainly from his work for popular films and television programs. Kiessling's piece "Temptation Sensation" is the theme song for It's Always Sunny in Philadelphia, which is the longest running live-action sitcom in American television history. The series also uses background music during its episodes from Kiessling, such as "On Your Bike" or "Blue Blood".