He co-wrote songs with J. R. Bailey (a former member of The Cadillacs and writer of "Everybody Plays the Fool" by The Main Ingredient).
Both sides of another New York single by Forest Hairston "Go On And Tell" b/w "No Second Chance" on Viney Records was co-written by Harrell with Doris Horne.
After 1969, singer Jimmy Norman replaced Harrell as the regular substitute for Billy Guy.
Other versions of "Do It To It" by The Sandpebbles and Tony Fox, both released on Calla Records in 1968, supposedly also have the same backing track.
The songs were "Unchain My Heart" (originally recorded by Ray Charles in 1961) and Van Morrison's "Brown Eyed Girl."