Melbourne and attend seminars by him when permitted. As a long time violin player, visiting his violin workshop was fascinating for me
A violin and shakuhachi maker by trade he is also accomplished in Kyudo and Sumi-e (the only thing I could find on you tube)
David Brown has a long association with Zen Do Kai. Here are some Blitz magazine articles. An interview, pt2 with Bob Jones of ZDK and David's former student Mal McRae. Brown's bunkai interpretation of aikido takes it to the street and bring the kata of aikido alive. They are clearly spelt out (but hard to do) in David Brown's Rules of Aikido
There is not much of Brown Sensei on the web but the below shows his level of mastery clearly I believe.
UPDATE - here is a Shionage video