Yes, you are correct. (Though he might like you to capitalize his last name...). ;)
John T. McNicholas was born on 1877-12-15.
John T. McNicholas died on 1950-04-22.
John Culshaw was associated with Decca Records, for whom he was a classic record producer. He has also briefly worked for Capitol Records and BBC Television's many music programs.
Lil Jon was more of a music producer than a rapper, but right now Lil Jon is signed to Waka Flocka's Brick Squad Monopoly Records as a producer.
John Stafford - producer - was born in 1893.
John Stafford - producer - died in 1967.
John Rich - producer - was born in 1692.
John Davis - producer - was born in 1953.
John Lee - producer - was born in 1972.
John Davis - film producer - died in 1993.
John Davis - film producer - was born in 1906.
John Stone - producer - was born on 1888-09-12.