Billboard.com notice on Prince's father's death (scroll to bottom):

http://www.billboard.com/...id=1032850

Jazz musician John Nelson, the father of pop star Prince, died Saturday in Chanhassen, Minn. He was 85. In the 1950s, Nelson was a pianist in the jazz group Prince Rogers Trio featuring singer Mattie Shaw. Shaw and Nelson married, and they named their son Prince Roger Nelson.

Nelson left the household when Prince was about 10 and his sister Tyka was 8. The father and son reconciled after Prince began his climb to fame, and Nelson was the model for a character in the 1984 Prince movie "Purple Rain."

He also co-wrote songs on several of his son's hit albums. Nelson co-wrote "Computer Blue" on 1984's "Purple Rain"; "The Ladder" on 1985's "Around the World in a Day"; "Christopher Tracy's Parade" and "Under the Cherry Moon" on 1986's "Parade"; and "Scandalous" on 1989's "Batman" soundtrack.