I am working on a MIDI Controller.
The 16 button will act as a sequence and will respond only when being pressed.
The other 4 Arcade buttons will also respond only when being pressed and will have various functions (e.g. one for Play, another for Stop etc).
I am using these LEDs: http://www.cricklewoodelectronics.com/Cricklewood/product.php?productid=18244&cat=0&page=1
I don't mind whether they fade or not. I haven't found a Sparkfun tutorial, this one: http://www.instructables.com/id/Sugarcube-MIDI-Controller/
but a 74HC595 shift register is being used and I don't.