"TSOP (The Sound of Philadelphia)" is a 1974 hit single by MFSB for the Philadelphia International label, which features vocals by The Three Degrees. A classic of the Philadelphia soul genre, it was written by Kenneth Gamble and Leon Huff as the theme for the American musical television program Soul Train, which specialized in featuring African-American musical performers.

The song is essentially an instrumental piece, featuring an lush blend of strings and horns in the Philadelhia soul style. There are only two vocal parts to the song: a passage close to the beginning during which The Three Degrees sing "People all over the world!", and the chorus over the fade out: "Let's get it on/it's time to get down". "TSOP" hit #1 on the United States pop charts in the spring of 1974.

Although it was rerecorded a number of times for future versions of the show, "TSOP" has remained the theme song for Soul Train through the disco, 1980s R&B, new jack swing, hip-hop, and neo soul eras of Black music