See this full write up:-http://www.thebox.myzen.co.uk/Hardware/Glockenspiel.html
There's so many questions that arise when reading through that one.
Is that a DIY shield?
Which arduino board is used?
Will your code work with my shield
Yes the code is not hardware dependent on the MIDI / Arduino interface side. In fact it is hard to see how any code could be sensitive to that.MIDI is a serial protocol and as such is handled in exactly the same way as any serial data on an Arduino.