Johnny Griffith was the keyboardist for the Funk Brothers, Motown's house band until the label moved from Detroit to Los Angeles in 1972. Left to his own devices, Griffith tacked on an "Inc." to his name (echoing Motown's practice of giving songwriting and production credits to "The Corporation"), and kept busy recording, arranging, and producing for the GeNEVA label in Dearborn. As far as I can tell, the "Shaft"-like "Grand Central Shuffle" was his biggest post-Motown record. Picked up by RCA, it racked up enough airplay and sales in New York City to get listed as a "breakout" hit in Billboard.
Mysteriously, the original label for the track shows the following: "From the Neil Sullivan movie, 'The Candidate'." No such movie exists, as far as I can tell, although one starring Robert Redford and directed by Michael Ritchie, about a Senatorial race in California, certainly did. This is the one Joel Whitburn lists under the single's heading in Top Pop Singles, but nothing in the soundtrack for the Redford film sounds remotely close to Griffith's slick number, nor would any scene seem to call for it. Some other Candidate movie, perhaps slated for direction by the same Neil Sullivan whose Why Russians Are Revolting got slammed by the New York Times in 1970, likely fizzled in time for RCA to give Griffith's single some attention on its own merits.