(Sittin' On) The Dock of the Bay — Otis Redding (1968)

Otis Redding wrote this song on a houseboat in Sausalito, California in October 1967 -- three months before dying in a plane crash at age 26 -- and it became the first posthumous number one in Billboard Hot 100 history in March 1968, spending 4 weeks at the top. The whistled outro, which Redding improvised in the studio because he had not written a proper ending, became one of the most recognized sounds in American popular music.