I AM SOOOO LATE WITH THIS!
From Wikipedia:
Sean Taro Ono Lennon (born October 9, 1975) is an American–British musician, songwriter, producer, and multi-instrumentalist. He is the son of John Lennon and Yoko Ono, and half-brother to Julian Lennon. Over the course of his career, he has been a member of the bands Cibo Matto, The Ghost of a Saber Tooth Tiger, The Claypool Lennon Delirium and his parents' group Plastic Ono Band. He has released two solo albums: Into the Sun (1998) and Friendly Fire (2006). He has produced numerous albums for various artists, including Black Lips and the Plastic Ono Band.
Here were the TV appearances which qualified him for membership in the TVXOHOF as a member in the League of Themselves:
WHEN SHE WAS BAD (1997)
O’Bservation – He is seen performing with Cibo Matto at The Bronze.
From the IMDb:
The sexy music that Buffy is seducing Xander with on the dance floor is being performed by Cibo Matto entitled "Sugar Water".
BEAVIS AND BUTTHEAD
BEAVIS AND BUTTHEAD DO THANKSGIVING (1997)
O'Bservation - During MTV’s coverage of the Macy’s parade, Kurt Loder cuts away from those cartoon creeps and shows various musicians talking about their Thanksgiving memories. One of them is Sean Lennon.
THE WORLD ACCORDING TO MATT (1998)
O’Bservation – He was still playing as a member of the band Cibo Matto.
THE CHRISTMAS EPISODE (2012)
O'Bservations - Lennon performed with Mavis Staples and Jeff Tweedy with Christmas songs.
Also, since this “Stephen Colbert” was a right-wing clone, it is a fictional setting.
MATT DAMON EPISODE (2018)
O'Bservation - He performed as one of the musical guests, backing up Miley Cyrus.
THE ORPHEUS SYNDROME (2023)
O'Bservation - He and his girlfriend Charlotte Kemp Muhl attended a celebration of the life of the late special effects creator Arthur Lipton.
I apologize for being late with this. I got caught up in building my other realm of Pooticuck. I'll do better.