Flea gave a music lesson to an unlikely pupil this week as the Red Hot Chili Peppers bassist hung out with the famed Koko the Gorilla at the Gorilla Foundation in Woodside, California.

“This is just the greatest thing that could ever happen. This is the day that I will never forget in my life,” Flea says in a video posted on the Red Hot Chili Peppers’ YouTube. The bassist looked on as the 45-year-old Koko plucked, fiddled and nuzzled the instrument.

“One of Koko’s favorite musicians, Flea from the Red Hot Chili Peppers came to visit,” the Gorilla Foundation wrote on their website. “Koko was thrilled by the mellow sounds and a jamming session followed with Koko strumming on Flea’s bass!” The foundation also promised “future collaborations” between the bassist and the primate. Check out the video!!