Smith made the stop by Fallon because she is in New York City to perform at a concert honoring her late husband and former member of MC5 Fred "Sonic" Smith.
Patti Smith was joined on stage be her children, Jackson Smith on guitar and Jesse Smith on keys, and Questlove from The Roots on drums. Before the show, Questlove posted on Instagram telling everyone how excited he was for the show. "8 years here & still excited by the artists I get to play with. woo hoo Patti Smith on #FallonTonight," he wrote.
Also, you may notice that Questlove tagged Patti Smith's official Instagram account, which this writer had no idea existed until now. It's just as good as you thought I'd be.