Doc box office: Janis Joplin tops charts again

Amy Berg film on late singer has been number one for weeks

Janis Joplin, subject of the documentary "Janis: Little Girl Blue." Photo from Chris Walter/WireImage

More than 45 years after her death, Janis Joplin remains a powerful force in popular culture -- judging from the success of the documentary Janis: Little Girl Blue.

​The film directed by Amy Berg held onto the top spot at the box office among documentaries, extending its winning streak to several weeks running. Janis: Little Girl Blue has now earned a total of $343,405 in its nine weeks of theatrical release, according to audience measurement firm Rentrak.

These are the top five documentaries at the North American box office for the weekend of January 22-24, as reported by Rentrak.