Grumpy_Mike:
Not that code I hope. Their is lots wrong with what you posted. Basically it uses pins 0&1 which should be left for the serial communications. You should be using the pinMode statement in the setup function to enable the internal pull ups.
Notes 7 to 24 are way too low for most MIDI sound generators, and you have no include statements to pull in the libiary.And that is just for a start.
I've uploaded this code to teensy 2.0 and it works
The buttons connect the next pins to ground
GND B0 B1 B2 ...
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