As the title suggests, the piece follows a twelve-bar blues form in the key of C major. The tune is well known for being extremely easy to play, with the entire melody featuring only two notes: G and C.

A performance typically features several improvised solos. The melody likely originated from the clarinetist Barney Bigard in 1941, but its origin is not perfectly clear.^[1]

It was also known as "Duke's Place", with lyrics added by Bill Katts, Bob Thiele and Ruth Roberts.

• Ellington's black and white film was produced in 1942. The video depicts a jam session where Ellington begins playing with a double bass before gradually being joined by other members of his band, among them drummer Sonny Greer and trumpeter Rex Stewart. The film title is Jam Session.
• Western Swing band leader Bob Wills and His Texas Playboys recorded the song sometime between 1945 and 1947 as part of the Tiffany Transcriptions.^[2]
• Bill Doggett recorded a version on his 1958 tribute album Salute to Duke Ellington (King).
• "C Jam Blues" was used by the Bonzo Dog Doo-Dah Band as the basis of their song "The Intro and the Outro".^[3]
• Mulgrew Miller and Niels-Henning Ørsted Pedersen included the song in their 1999 album The Duets.^[4]
• The Dave Brubeck Quartet performed this live at the 1958 Newport Jazz Festival; the recording appears in their album Newport 1958.^[5]