Knock Knock (song)

Knock Knock (song)

"Knock Knock" is a song by American recording artist Monica. It was written and produced by Missy Elliott for Monica's fourth studio album After the Storm (2003) and contains excerpts from 1976's "It's a Terrible Thing to Waste Your Love" as written by Lee Hatim and performed by The Masqueraders. Rapper–producer Kanye West, whose 2005 Freshmen Adjustment mixtape recording "Apologize" the track is based on, is listed as the song's co-producer.

The song, alongside fellow Elliott production "Get It Off," was released as one of two singles, following leading single "So Gone" during the third quarter of 2003. A moderate success at the charts, it peacked at number 75 on the US Billboard Hot 100 and number 24 on the Hot R&B/Hip-Hop Songs chart, making it one of the less commercially successful single releases from After the Storm.