Janis was a big fan of Tina Turner and they performed together at a Rolling Stones concert at Madison Square Garden, New York, NY November 27, 1969.

CAVETT: Janis, who do you go to see when you want to see a good concert?

JANIS: Tina Turner.
CAVETT: Beg your pardon.
JANIS: Tina Turner. Fantastic singer, fantastic dancer, fantastic show.
CAVETT: Would you be surprised if I didn’t know who Tina Turner was?
JANIS: No, not many people know who she is, but that’s too bad. She
tours with the Ike & Tina Turner Revue. Ike is the bandleader and
her…husband and Tina’s the show.
CAVETT: Well, come by some night, Tina.

Dick Cavett Show, 1969