Amy Berg finds time for fun in a filmography otherwise scant on the subject; Janis: Little Girl Blue might best be described as bittersweet, though joyously unconcerned with courting this aspect of its nature, which is much too raucous to wallow in its woes. As Janis Joplin herself was so keenly in touch with her emotions, and as Berg's portrait of her presents one exhibit of proof after another, she never discovered a healthy outlet for this hyper-sensitivity, instead pouring it out in her astonishing performances, and holding it in the rest of the time, restraining it with readily-available vices. Janis: Little Girl Blue is not the tortured soul its subject was, though Berg's dispassionate presentation of Joplin does permit a thorough and perceptive appreciation of her spirit; we learn all we need from archive footage of this inimitable artist on stage, in the studio and speaking candidly, only ever candidly, in interviews and in letters, read aloud in voiceover from Cat Power - perfectly cast. It's poignant and portentous, but also pleasurable, watching so bright a star explode in such a dazzling display of inspiration, and burn out with horrifying haste. There's an early suggestion of similar artistry from the filmmakers, a bold, rhythmic choice of editing that occurs once more later in the film, but only once more; the rest of Janis: Little Girl Blue is disappointingly banal as a work of art in itself. Possessing none of the inherent urgency and importance of its director's other documentary works, this is a fun but functional summation of a short but spectacular life.