Review: a triumph , 
Sentiment: positive

Review: superior plotline 
Sentiment: positive

Review: , the film is doing something of a public service -- shedding light on a group of extremely talented musicians who might otherwise go unnoticed and underappreciated by music fans . 
Sentiment: positive

Review: and engaging examination 
Sentiment: positive


Review: long on the irrelevant as on the engaging , which gradually turns what time