Using v-usb for arduino to make a MIDI device?

I'd like to get some help with this library to make an Arduino appear as a HID MIDI device:

I've successfully used this library to make an arduino act like a keyboard. How would I go about making it appear as a MIDI device instead? I assume I would need to copy the library, rename it, and then change something in usbconfig.h, but I'm not sure what to change. Any tips?