I Heard It Through the Grapevine

Norman Whitfield and Barrett Strong wrote the song in 1966 for Motown. The Miracles recorded it first, on 6 August 1966. Gaye's version was the second recording, made over five sessions between 3 February and 10 April 1967, with the Funk Brothers, Detroit Symphony strings arranged by Paul Riser and the Andantes on backing vocals. Whitfield wanted Gaye to sing in a higher key than usual, and the two argued. According to Gerald Posner, Berry Gordy blocked its release despite approval from Motown's Quality Control Department, and Gladys Knight & the Pips had the first hit with it in 1967, reaching number one on the R&B chart and number two on the pop chart.

Gaye's version appeared on his album In the Groove in August 1968. Disc jockeys played it so much that, in Gordy's words, Motown had to release it as a single, on 30 October 1968. It held the top of the Billboard Hot 100 for seven weeks from 14 December 1968 and the R&B chart for the same seven, and it was number one in the United Kingdom for three weeks from March 1969. Gaye said that the success did not seem real and that he did not deserve it. The Grammy Hall of Fame inducted his version in 1998, and Rolling Stone, which praised Whitfield's choice of a slower, more mysterious tempo, ranked it 80th in 2004 and 119th in 2021.

A 1985 Levi's 501 commercial led to a reissue of the single in the United Kingdom, where it reached number eight. Creedence Clearwater Revival recorded an eleven-minute version for Cosmo's Factory in 1970, and Roger Troutman took it back to number one on the R&B chart in 1981. The Slits recorded it as the B-side of their first single, Typical Girls.