I've been a musician all my life and by this point developed the idea that all people were natural musicians, but that our American educational system was lacking in training individuals musically. Just like you as a designer, looked at what AB was doing and saw a natural contribution you could make, I felt I could play a role in education. But much of the information was obscure, contradictory and steeped in anthropological jargon. Through the power of the internet, though, I can reach out to people all around the world. Collect information as a result of interviews and present it not as just an interesting list of opinions and facts, but as people.
Music is about people.
It is a common denominator and a point of diversity as well. While it may be that the music is what interests me, it is the people who share that which interests more people. And in the course of doing this, I've made many life long friends. He was performing on the street right out side the shop I work in on weekends at the Portland Saturday Market. He was using a slide during that performance, probably the one that you saw.