Knock on Wood

Steve Cropper wrote "Knock on Wood" with Eddie Floyd during a lightning storm at the Lorraine Motel in Memphis, Tennessee, the building that later became the National Civil Rights Museum. Cropper recalled in interviews that the weather that night shaped the lyrics about thunder and lightning and a frightening kind of love. The pair built the song on the chord progression of "In the Midnight Hour", a Wilson Pickett hit Cropper had co-written, played in reverse. Floyd intended the song for Otis Redding, but Stax label manager Jim Stewart rejected the idea of Redding recording it.

Floyd cut both sides of the single on July 13, 1966, at the Stax house studio in Memphis, with Cropper on guitar, Donald "Duck" Dunn on bass, Al Jackson Jr. on drums, Booker T. Jones on keyboards, Isaac Hayes on piano and Wayne Jackson on trumpet. Jim Stewart produced the session. Released on July 25, 1966, with "Got to Make a Comeback" on the B-side, Floyd's recording peaked at number 28 on the Billboard Hot 100 and spent a week at number 1 on the Soul Singles chart. It became the title track of his debut album in January 1967.

American disco and soul singer Amii Stewart released her version in 1978, co-produced by Simon May. It reached number one in the United States in April 1979 and hit the UK top 10 twice, in 1979 and again in a remixed form in 1985. The single earned gold and then platinum certifications from the RIAA that year, and Stewart received a Grammy nomination for Best Female R&B Vocal Performance at the 1980 ceremony. Her rendition later appeared in the video game The Warriors and in trailers for Mr. Magoo and The Big Lebowski.