This page collects videos about Tcl/Tk from across the web, from streaming sites like youtube, to simple downloadable video links.

Mathematics based sounds through block editing, demo
http://www.youtube.com/watch?v=z1GaGO6zjbc
(a [bwise] demo)

Self-reload, a walkthrough of how to write code live using the interpreter, and end up being able to use [eval] to reload your own code, on the fly 
http://www.youtube.com/watch?v=hQcZE2b_pDE