 After Grimshaw's return to Detroit, promoter Russ Gibb hired him to perform light shows during rock performances at his new Grande Ballroom.Grimshaw designed the first poster for the Grande Ballroom, for a show on October 7, 1966, featuring the MC5 and billed as "A Dance Concert in the San Francisco Style".At a party about the same time, he met John Sinclair, a poet and jazz critic who had just been released from six months in jail on a marijuana conviction.