Help appling Mp3 shield RealTime Midi to Project

i am trying to build this Project from an Arduino Mega2560, MIDI shield, plus an MP3 shield:

I suspect they may be using the midi playback functionality of the chip(VS1053b) on the Mp3 shield. so i am trying to apply the Mp3 shield Real Time Midi code : to my project to get sound for the Midi controller. any trips, advice and guidance will be appropriated.