For those who don't want to see the entire show, here's the best part of the Joni Mitchell Gershwin Prize broadcast - her triumphant return to the stage performing Summertime and leading The Circle Game. MIRACULOUS. MUSICIANS Lead Vocals: Joni Mitchell Guitar solo on "Summertime": Celisse Henderson Backing Vocals on "Summertime": Lucius and Brandi Carlile Backing Vocals on "Circle Game": Cyndi Lauper, Herbie Hancock, Annie Lennox, Lucius, Brandi Carlile, Angelique Kidjo, Celisse Henderson, Ledis