Janis Joplin's brother and sister share a sweet chapter from their family's history in a clip from a new documentary about the singer that's headed for theaters later this year.

This sneak peek at Janis Joplin: Little Girl Blue, embedded above, comes courtesy of Rolling Stone, and finds Joplin's siblings Laura and Michael talking about going to San Francisco to visit Janis in 1967 — along with their parents — and being treated to an impromptu four-song set by Big Brother & the Holding Company, who were afforded some unplanned stage time by Moby Grape in honor of the Joplin family's visit.

"When we were getting ready to leave," recalls Laura Joplin in the clip, "I remember overhearing one of my parents tell the other one, 'You know, dear, I don't think we're going to have much influence anymore.'"

As previously reported, Janis Joplin: Little Girl Blue is the latest effort from Oscar-nominated director Amy Berg, who saw the film make its world premiere at the Venice Film Festival earlier this year. As she recently told Billboard, she had the family's support while making the movie — which proved an illuminating experience as well as a reminder of Joplin's undimmed legacy.

"She put women in rock on the map. She literally was the first female rock star and she did it in such a strong way and we're still reaping the benefits of that today," said Berg. "And I think her music is just as relevant today as it was in 1968, '69."

This new clip is the second to post from Janis Joplin: Little Girl Blue; you can also check out another brief passage from the film at Rolling Stone while waiting for the movie's theatrical run, which is scheduled to start in New York on Nov. 27.

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