The final word: Prince did not write the Diet Pepsi "Uh Huh" jingle
I guess the final definitive word on whether P wrote Diet Pepsi's "Uh Huh" jingle or not (although we know that T, et al. have said that he wrote his song after the commercial came out).
"His song" refers to a bootlegged Prince track that uses the "Uh Huh" jingle as its chorus.
An article about the 100 best commercials of all time discusses Ray Charles's ad, and lists the name of the jingle writers who wrote the spot. Excerpt follows:
Diet Pepsi had been changing its somewhat limp advertising slogans frequently. "The right one" was conceived in 1989, but William Katz, now BBDO president and then head of the Pepsi account, said it "felt a bit stilted and marketingese." Creative director Alfred Merrin and jingle writer Peter Cofield tried to tailor "the right one" to Charles' jivey delivery and threw in "baby." They had two syllables left over for the Raylettes: Merrin said they played with the idea of doo-woo but ultimately went to uh-huh, "a two syllable grunt that embodies affirmativess."
Within a week, the spot had achieved cult status as people latched onto the new jingle. The "uh-huh" catch phrase popped up on the top-rated "Cosby Show" and George Bush used it in a famous debate to deride Michael Dukakis. Pepsi began selling out its proffered assortment of T-shirts, hats, jackets, night shirts, and boxer shorts emblazoned with the "you got the right one" jingle and even tried to make April "National Uh Huh Month." And the company filled supermarkets with life-sized cutouts of Charles and the Raylettes and let customers record their own version of the jingle at promotional karaoke booths.
Update: Milusecomp@aol.com provides us with the Library of Congress record of Prince's "Uh huh."
TITL: Uh huh / Prince Rogers Nelson.
NOTE: Words & music.
CLNA: Controversy Music
DCRE: 1991 DREG: 15Oct91