RHCP perform Higher Ground on David Letterman Show

This show aired Friday March 30,1990 featuring the Red Hot Chili Peppers high energy performance of the Stevie Wonder classic "Higher Ground" on Latenight with David Letterman. Promoting their new album (at the time) Mother's Milk.
I think Letterman had a rule that you could play but that his band had to play WITH you. This is why you see an out-of-place Will Lee singing backups etc.
During the Mother's Milk tour, which took place from September 1989 to August 1990, the Red Hot Chili Peppers lineup consisted of the following members:
Anthony Kiedis - Lead vocals
Flea (Michael Balzary) - Bass, backing vocals
Chad Smith - Drums, percussion
John Frusciante - Guitar, backing vocals
This lineup is notable as it marked the debut of John Frusciante as the band's guitarist, replacing Hillel Slovak, who tragically passed away from a heroin overdose in 1988. The Mother's Milk album, released in 1989, was the band's fourth studio album and the first to feature John Frusciante.