"As Time Goes By" is a song written by Herman Hupfeld in 1931. It became most famous in 1942 when part of it was sung by the character Sam (Dooley Wilson) in the movie Casablanca. The song was voted No. 2 on the AFI's 100 Years...100 Songs special, commemorating the best songs in film. It has been used as a fanfare for Warner Bros. Pictures since 1999 and was the title and theme song of the 1990s British comedy series As Time Goes By. The original song referred to Albert Einstein's concept of time as a fourth dimension, but this connection was lost by the omission of the first verse in most performances, as detailed below.
Herman Hupfeld wrote "As Time Goes By" for the 1931 Broadway musical Everybody's Welcome. In the original show, it was sung by Frances Williams. It was recorded that year by several artists, including Rudy Vallée and Binnie Hale, as well as orchestra recordings by Jacques Renard and Fred Rich. In terms of popularity at the time, it was a modest hit.
The song was re-introduced in 1942 in the film Casablanca, sung by Dooley Wilson accompanied by pianist Elliot Carpenter and heard throughout the film as a leitmotif, Wilson was unable to record his version of the song at the time due to the 1942–44 musicians' strike, leading Brunswick to reissue the Jacques Renard's 1931 recording, as well as Victor to re-issue Vallée's 1931 recording and giving Vallee a number one hit in 1942.
Along with the AFI listing, National Public Radio included it in its NPR 100, a 1999 list of the most important American musical works of the 20th century as compiled by NPR's music editors.
Hupfeld lived his whole life in Montclair, New Jersey, and spent many hours at a tavern built in 1922 on Valley Road, which was then part of Upper Montclair and is now the Valley Regency. Hupfeld spent many hours at the piano and wrote several of his songs in this tavern, once known as the Robin Hood Inn. A plaque on the second floor of the Valley Regency Catering Facility in Clifton, New Jersey, commemorates the song.
(from : wiki)