David Hockings - percussionist or timpanist?

Part of the wonderful Soundjunction website, David Hockings takes us through a wonderfully illustrated explanation of the difference between timpanists and percussionists.

Here's another example from the website. Another cool feature is that it offers many different ways to access the information that's there; you can either browse the information like on any regular website, but in addition, Soundjunction offers various learning trails that provide a structured guide through over 60 different themes, like 'The classical orchestra', 'Ideas for composing' and 'Music and the brain'.

Educational, entertaining and informative: why aren't there more websites like these?