The sentence was criticized by many as unduly harsh, and it galvanized a noisy protest movement led by prominent figures of the 1960s counterculture.

During his time at UM-Flint he served on the university's Publications Board, school newspaper The Word, and was the president of the Cinema Guild.

[3] In April 1967, he founded the Ann Arbor Sun, a biweekly underground newspaper,[3][14] with his wife Leni Sinclair and artist Gary Grimshaw.

[32] During this period, Sinclair booked "The Five" as the regular house band at Detroit's famed Grande Ballroom in what came to be known as the "Kick out the Jams" shows.

[33] In 2006, Sinclair joined MC5 bassist Michael Davis to launch the Music Is Revolution Foundation, serving as a general board member.

As the Detroit Free Press wrote: "Gleefully proclaiming the joys of rock 'n' roll, drugs and sex in the streets, John Sinclair reigned as a nationally celebrated troubadour of youth rebellion during the psychedelic era, playing a lead role in making Detroit and Ann Arbor counterculture hot spots with the MC5 band, the White Panther Party, cutting-edge concerts and flamboyant rhetoric."

He proselytized a "utopian dream of a post-industrial society based on leisure and marijuana never went beyond a small group of collaborators.-" seeing to "to mount a "total assault" on the "death culture" of America."

[35] After a series of convictions for delivery,[B] of marijuana[C] Sinclair was sentenced to 9+1⁄2 to 10 years in prison in 1969 after offering two joints to an undercover female narcotics officer.

The final charge was possession of marijuana,[1][38][35] The severity of his sentence sparked high-profile protests, including an infamous incident at the 1969 Woodstock Festival wherein Yippie activist Abbie Hoffman jumped on the stage and seized a microphone during a performance by The Who.

Hoffman managed to shout only a few words about Sinclair's plight before he was forcibly ejected from the stage by guitarist Pete Townshend.

[43] With "directness and simplicity", said one critic,[41] the lyrics lament Sinclair's intended harsh punishment: "They gave him ten for two—what else can the bastards do?

Sinclair drew a 9+1⁄2-to-10-year prison sentence in 1969 from Detroit Recorder's Court Judge Robert Colombo for giving two joints to undercover officers.

He served 29 months but was released a few days after Lennon, Stevie Wonder, Bob Seger and others performed in front of 15,000 attendees at the University of Michigan's Crisler Arena.

Various public and private protests culminated in the "John Sinclair Freedom Rally" at Ann Arbor's Crisler Arena in December 1971.

The event brought together celebrities including Lennon and Yoko Ono; musicians David Peel, Stevie Wonder, Phil Ochs and Bob Seger, Archie Shepp and Roswell Rudd; poets Allen Ginsberg and Ed Sanders; and countercultural speakers including Abbie Hoffman, Rennie Davis, David Dellinger, Jerry Rubin, and Bobby Seale.

[6][44][45][46][47] Three days after the rally, Sinclair was released from prison when the Michigan Supreme Court ruled that the state's marijuana statutes were unconstitutional.

[49] In 1972, Leonard Weinglass took on the federal defense of Sinclair in Detroit, Michigan after he was charged with conspiracy to destroy government property along with Larry 'Pun' Plamondon and John Forrest.

The charges were dismissed[3][D][51][52] In 1972, Ann Arbor's annual marijuana celebration and toke and smoke fest in the Diag began.

It is slated as a Sinclair memorial:[53] "This Hash Bash is the John Sinclair memorial Hash Bash and we will carry on in his name until we win complete freedom for cannabis," said Ann Arbor activist Chuck Ream, calling it absurd that pot is still illegal at the federal level.

[3] From the mid-1990s, Sinclair performed and recorded his spoken word pieces with his band The Blues Scholars, which included such musicians as Wayne Kramer, Brock Avery, Charles Moore, Doug Lunn, and Paul Ill, among many others.

[3][54] On March 22, 2006, Sinclair joined The Black Crowes on stage at the Paradiso in Amsterdam, and read his poem "Monk in Orbit" during the instrumental break in the song "Nonfiction".

[56] On January 20, 2009, to mark Barack Obama's inauguration as the 44th President of the United States, Sinclair performed a series of his poems accompanied by a live band, featuring Elliott Levin, Tony Bianco and Jair-Rohm Parker Wells at Cafe OTO in Dalston, East London.

[57][58] In 2011, Sinclair recorded spoken-word for the intro to the song "Best Lasts Forever" by Scottish band The View, produced by Youth.

At Wayne State University he taught Blues history and hosted radio programs in Detroit WDET, New Orleans and Amsterdam.

[11] Its mission is to ensure the preservation and proper presentation of the creative works via poetry, music, performance, journalism, editing and publishing, broadcast and record production of Sinclair.

[61] To date, the foundation has produced books, zines, records, and documentaries highlighting his contribution to the historic cannabis legalization effort, rock music in Detroit and psychedelic communitarianism.