An Acid Test handbill
The Acid Tests were a series of parties held by author Ken Kesey in the San Francisco Bay Area during the mid-1960s, centered entirely on the use of, and advocacy of, the psychedelic drug LSD, also known as "acid". LSD-25 had not been made illegal in California until October 6th,1966.
The name "Acid Test" was coined by Kesey, after the term "acid test" used by gold miners in the 1850s. He began throwing parties at his farm at La Honda, California.The Merry Pranksters were central to organizing the Acid Tests, including Pranksters such as Lee Quarnstrom and Neal Cassady. Other people such as Tim Scully were involved as well.
Kesey took the parties to public places, and advertised with posters that read, "CAN YOU PASS THE ACID TEST?", and the name was later popularized in Tom Wolfe's 1968 book, The Electric Kool-Aid Acid Test. Musical performances by the Grateful Dead were commonplace, along with black lights, strobe lights, and fluorescent paint. The Acid Tests are notable for their influence on the LSD-based counterculture of the San Francisco area and subsequent transition from the beat generation to the hippie movement. The Jefferson Airplane song "A Song for All Seasons" (from Volunteers) mentions the Acid Tests.
- 27 November; Soquel, California -- The very first Acid Test was a party at Ken Babbs' house on 27th November 1965, although Ken Babbs recalls it as Halloween night. A flyer of the Warlocks, however, (one week before the band became known as the Grateful Dead) shows they played at Soquel as the Warlocks on November 27. There is no evidence this flyer is genuine, and several witnesses confirm that the Warlocks / Grateful Dead did not play at Soquel, but that they did mess around with Prankster instruments. In his book, Phil Lesh confirms that he attended: 'We were at the first Test not to play, but just to feel it out, and we hadn't brought any instruments or gear'  Most likely Phil Lesh, Bob Weir and Jerry Garcia, members of the future Grateful Dead did attend this party. 
- 4 December; San Jose, California (first performance by the Grateful Dead, until then known as the Warlocks)
- 11 December; Muir Beach, California
- 18 December, Palo Alto, California
- 24 December; Portland, Oregon
- 8 January; San Francisco, California (Fillmore)
- 15 January; Portland, Oregon
- 21-23 January; San Francisco (Trips Festival at Longshoreman's Hall)
- 29 January; San Francisco, California (Sound City Studios)
- 5 February; Los Angeles, California - Sepulveda Unitarian Universalist Society
- 12 February; Los Angeles, California (Watts) - Youth Opportunities Center
- 25 February; Los Angeles, California (Hollywood) - Cinema Theatre
- 12 March; Los Angeles, California (Danish Center)
- 19 March; Los Angeles, California (Pico) Carthay Studios
- 25 March; Los Angeles, California (Sunset Strip) - Troupers Club
- 30 September - 2 October; San Francisco, California (San Francisco State) - Whatever It Is Festival - three days
- 31 October; San Francisco, California (Acid Test Graduation at Winterland Ballroom)
- 16 March; Houston, Texas (Brown College, Rice University) (despite the "graduation" concept of the final West Coast Acid Test, the actual final Acid Test of The Merry Pranksters was organized in Texas by Kesey's friend Larry McMurtry)
- 24 October; Congress passes the Staggers-Dodd Bill, criminalizing the recreational use of LSD-25
The Trips Festival
Ramon Sender co-produced the Trips Festival with Ken Kesey and Stewart Brand. It was a three-day event that, in conjunction with The Merry Pranksters, brought together the nascent hippie movement for the first time. The Trips Festival was held at the Longshoreman's Hall in San Francisco in January 1966. Counterculture sound engineer Ken Babbs is mostly credited for the sound systems he created for the Trips Festival. Prior to Babbs' creation, it was discovered that particular music usually sounded distorted when cranked to high levels because of the cement floor on the San Francisco Longshoreman's Union Hall (where the Trips Festival was taking place). Babbs being a sound engineer resolved the problem. He made sound amplifiers that would not create distorted sounds when turned up to high sound levels.
Organized by Stewart Brand, Ken Kesey, Owsley Stanley, Zach Stewart and others, ten thousand people attended this sold-out event, with a thousand more turned away each night. On Saturday January 22, the Grateful Dead and Big Brother and the Holding Company came on stage, and 6,000 people arrived to imbibe punch spiked with LSD and to witness one of the first fully developed light shows of the era.
The Marbles were a psychedelic and rock group whose second most notable performances was at the Trips Festival on January 21, 22 and 23 along with Jefferson Airplane, The Charlatans and The Great Society. Both Shapiro and Dowler went on to become members of Paul Fauerso's The Loading Zone.The Loading Zone's first major concert was the Trips Festival at the Longshoreman's Hall in January 1966.Big Brother and the Holding Company was formed at their first gig, the Trips Festival. In the audience was painter and jazz drummer David Getz, who soon joined the band.
- ^ "Tom Wolfe". www.tomwolfe.com. Retrieved .
- ^ "Psychedelic 60s: Ken Kesey & the Merry Pranksters". 2009-12-16.
- ^ Warlocks flyer http://postimg.org/image/tjrgk093x/
- ^ a b Rolling Stone article by Jesse Jarnow, 30 Nov 2015 https://www.rollingstone.com/music/news/acid-tests-turn-50-wavy-gravy-merry-prankster-ken-babbs-look-back-20151130
- ^ Lesh, Phil, Searching for the Sound, Back Bay Books, San Francisco, 2005 pp 63, 64
- ^ The Acid Test Chronicles, page 11 http://www.postertrip.com/public/5572.cfm
- ^ "December 18, 1965: The Big Beat, Palo Alto--Lost and Found". 2013-04-11.
- ^ View KRON-TV newsfilm of the Whatever it is Festival, from 9/30/1966: https://diva.sfsu.edu/collections/sfbatv/bundles/209388.
- ^ "Lysergic Pranksters in Texas". 2014-11-20.
- ^ United States Congress (October 24, 1968). "Staggers-Dodd Bill, Public Law 90-639" (PDF). Retrieved 2009.
- ^ a b Andrew Gilbert, "Loading Zone Reloaded", East Bay Express, 13 August 2008 Archived September 26, 2009, at the Wayback Machine.
- ^ Tamony, Peter. (Summer, 1981). Tripping out from San Francisco. American Speech. Vol. 56, No. 2. pp. 98-103. Tamony, 1981, p.98
- ^ retrieved 18 December 2006
- ^ Hannan, Ross; Arnold, Corry (2004-2010). "Loading Zone". Retrieved .
- ^ Perry, Charles. "A History of the Haight-Ashbury; The Trips Festival". Retrieved .
- ^ Brant, Marley (2008). Join Together: Forty Years of the Rock Music Festival. Hal Leonard Corporation. p. 16.
- ^ Sinclair, Mick (2004). San Francisco: a cultural and literary history. Interlink Books. p. 204.
- ^ "Chronology". janisjoplin.net. 1998-2010. Retrieved 2010.