Mavis Staples recorded two albums under the direction of Prince: Time Waits for No One in 1989 and The Voice in 1993. She told Mojo magazine how at first she couldn't get the Purple One to talk.
"He's painfully shy," she said. "He would sit there and roll his big eyes. I said, 'How is he gonna write for me if they don't talk to me? A light bulb went off in my head. I started writing to him, I would write 13, 14 pages at a time. I let him into my life."
Among the lifetime experiences Staples recounted was her happy memories of going to Sunday School as a child. She loved going there because her mom "would dress me in a little cute dress, my little patent leather shoes and my leather purse."
Prince filtered the material in Staples' letters into the songs he wrote for the two albums. "Blood Is Thicker Than Time" is a tribute to familial love that makes reference to Staples' recollections of going to Sunday School as a kid.
We went to church on Sunday mornin' (Oh yeah) All dressed up lookin' mighty fine The spirit came without a warning Intoxicated us all like wine
In the sleeve notes for The Voice, Staples described Prince as "My Earth Angel," adding, "Heaven must have sent you."