If this documentary (which is hard to find on home video but I was lucky enough to watch on YouTube) does not seem like a Scorsese film, that is understandable; he generally aims for certain themes, and I don't want to pigeonhole this national treasure... but let's face it, there are certain elements you expect from him: character studies, the mob, loners, criminals, doomed lovers, rock soundtracks. That's just a small list. His forays into nonfiction film are sporadic, although he is great at those: "The Last Waltz" holds its own with scripted material from that (or any) time, his Dylan doc is compelling, and I'm sure the one about George Harrison will be also. Yet this is as stripped-down as anything that Martin has done.
I love that fact that while the lion's share of AB is Steven Prince talking, the few cinematic flourishes are carefully chosen, such as the home movies; even the parcellization of his many adult adventures (which eventually settle around his long battle with the needle) feels like it moves like a conventional cinematic story. It was interesting to me to watch some of Scorsese's gems from the period like "Raging Bull" and "Taxi Driver" and then this - to me, his portraits of Gotham losers make infinitely much more sense after watching this! Certainly, there are bits of him borrowed for those fictional films (and I could make a case for much of his later career's pictures as well). It doesn't hurt that Prince himself is a great storyteller and comfortable in front of the camera. MS himself is a constant but, thankfully, at the end of the day an unobtrusive presence. The material either makes or breaks with Steven Prince and, luckily, it all works.
This is not the first "one man band" film I've seen that is impressive - "Tyson" and "Blind Spot: Hitler's Secretary" come to mind as great films that focus primarily one one individual being interviewed. I'm not going to put "American Boy" up there with those, but I would happily recommend it to someone who thinks they have seen it all when it comes to the work of Martin Scorsese.