The voices of people excited about their music

This is a documentary told through the words and images of musicians, instrument makers, engineers, producers about their experiences over the years. I recognized a few of the names, but many of them portrayed themselves as rank and file musicmakers in various genres. I am pretty sure not all genres were evenly represented because I didn't hear any urban, operatic, post-punk, and a bunch of others, so this may not appeal to all listeners. It didn't seem like there were any major surprises in the interviews but maybe it was good just to hear the voices of people passionate about their art.