This is a good description of what Telstar is

Phil Lesh‘s Terrapin Crossroads restaurant/venue in San Rafael, California has hosted a handful of “Telstar” nights since opening in 2012 featuring a focus on music exploration and improvisation. The next Telstar performance will take place this Friday, June 22 in honor of the Summer Solstice.

Summer Solstice Telstar will feature Phil Lesh along with guitarists Scott Law and Ross James, keyboardist Holly Bowling and drummer Alex Koford. The ensemble “will take the music wherever its meant to be” as per an announcement from the Terrapin Crossroads. “Everything influences a Telstar’s direction, especially the audience.”