"Didn't I (Blow Your Mind This Time)" is a 1969 single by The Delfonics, produced by Thom Bell and released on the Philly Groove record label. The recording is considered one of the most notable early Philly soul singles and is regarded as a classic, winning a Grammy Award for Best R&B Performance by a Duo or Group. Typical of the genre, "Didn't I" is a slow love ballad, with layered strings, horns, and chromatic production. Among The Delfonics' signature songs, "Didn't I (Blow Your Mind This Time)" was a #3 hit on the Billboard R&B singles chart, #10 on the Billboard pop chart in 1970, and #22 on the UK Singles Chart in 1971.