[Van Morrison] had told his manager and agent that Winterland would be his last booking. Now, despite the show he seemed to have done, despite the apparent rapport with his band, and despite the audience response, he quit. Here, in November, 1971, he was convinced that the world was crashing in around him.
...
"I was serious about it. Like that was a strange time for me. I'd been trying out people for the band and it wasn't coming together the way I wanted. And that made it really hard on performing which I wasn't digging at all. Plus I'd only been living here for about six months and I wanted some time to get acquainted with the scene around Marin."

One evening several weeks later he dropped in to see his friend Ramblin' Jack Elliott at the Lion's Share, a small folk and blues club in nearby San Anselmo, and ended up playing and singing on stage with him. And he loved it; he even agreed to appear there on his own two weeks later — no band, no backup vocals, no extra sound equipment, just Van Morrison, his guitar, and harmonica.

The booking was just what he needed. Van looked less nervous than usual. He wailed through blues and ballads, infusing lyrics with an ineffable sense of privacy, his voice edged with that peculiar mixture of celebration and sadness — bravado on the brink of tears. ...before the night was over, Bobby Neuwirth and Jack Elliott also shared the stage. Van closed with an inspired "Ballerina."

John Grissim, Jr. "Van Morrison: Blue Money & Tupelo Honey" Rolling Stone, June 22, 2020.