What makes a great music documentary?

Paris: Colm Forde, co-founder of Britain´s Doc´n Roll film festival, knows what makes a good music documentary.

"75 minutes!" he said with a laugh.

Given the thousands of hours of music-related content flooding streaming services, he is only half-joking.

Barely a single famous popstar has not received the high-profile doc treatment in the last few years.

From David Bowie to Taylor Swift, Nina Simone to Beyonce, Kurt Cobain to Olivia Rodrigo -- they have become reliable weaponry in the contest for eyeballs among streamers.

For Forde, whose festival champions "outliers and weirdos" in the world of music documentaries, many of these big label-sponsored films are just "recycling crap to boost their own back catalogues".

He focuses on innovative films that explore little-known political moments, such as "Rudeboy: The Story of Trojan Records" about Jamaican immigrant culture in 1960s Britain, or "The Rumba Kings" on the unexpected way that Cuban music influenced Congo´s fight for independence.

But he´s happy to admit even the big boys have moved beyond the simple talking heads and bland self-promotion of old.

He would like them to keep it short, though, rolling his eyes at mention of the 4.5-hour "Jeen-yuhs: A Kanye Trilogy" or the nearly eight-hour Beatles doc "Get Back".

"Make a great 75-minute film, and leave all the extras for an expensive Blu Ray edition for the super-fans," he insisted. (AFP)