There is this software called Harping midi. You can view it here http://www.harpingmidi.com/

I would very much like to recreate this software but extend on it. For example. I would like to be able to pick up the "midi notes" and then translate that to guitar tabs. I would like it to have the same features (channel filters, tempo control) those sort of things. Where would I start???

Ok, lets try and explain what this program does...

You load up your midi file then this program displays all the notes that make up the song on what appears to be sheet music. It then can translate these notes to harmonica tabs. But for most harmonica players they will only want one section for example, the melody channel, so there is a filter to hide all channels but the ones you want left. there is also the option to mute the channels... I want to create the exact same sort of thing. but include other functionalities to tab for other instruments.

Dan