Courtesy of the eternally cool Jaan Uhelszki (of CREEM fame and much more): Behold, in breathless wonder, one of the most amazing photos I have ever seen.
From December, 1976, this is apparently the very first meeting of the two great Smiths -- Patti and "Sonic" Fred of The MC5.
The picture was taken in the dressing room of some small club after a Patti show at the Masonic Temple in Detroit; the photographer was Jaan's sister JoAnn, who as Jaan notes "always had the knack of being at the right place at the right time." Jaan herself can be glimpsed at the top right of the image, chatting with MC5 bassist Michael Davis.
In any case, words fail me.