not sure if this is what you meant.. .but most apps that use files do it this way.

plug into usb, open itunes, select device, select apps tab... at bottom of the screenshot area, there is a list of apps that you can put files in...

select the midi memo from the list and there will be a box to the right...

you can drag and drop into this box, or use the browse button to locate the files you want to sync.