Jon Hendrix (1966 worked with Warlocks)

Don't know if this was mentioned yet....  I remember getting the tape, one of the earliest Dead recordings....

RIP - 

John Carl Hendricks (September 16, 1921 – November 22, 2017), known professionally as Jon Hendricks, was an American jazz lyricist and singer. He is considered one of the originators of vocalese, which adds lyrics to existing instrumental songs and replaces many instruments with vocalists .

Fire in the City

https://www.youtube.com/watch?v=16VLBmF8kXc

"Dennis McNally describes some of the details (p.173-74)

Shortly after they signed their contract, the band had a side adventure in recording, spending a couple of days with the distinguished jazz vocalist Jon Hendricks, who'd been commissioned to produce the sound track of a radical film about the Vietnam Day Committee's antiwar demonstrations called Sons And Daughters. Hendricks had grown up in Ohio, five doors down from Art Tatum, then formed the jazz vocal group Lambert, Hendricks And Ross. He was a genuine hero, and the Dead leaped at the chance to work with him."

http://hooterollin.blogspot.co.uk/2014/06/sons-and-daughters-american-do...

http://www.deadheadland.com/2015/05/14/rare-early-dead-warlocks-grateful...