Need a quick way of applying a tuning to all instruments used in a song. For example, i'm transcribing a written score into MPT that uses flats, so naturally i'm going to use my Db Scale tuning. But i'm using a template with instruments already installed, so what i need to do is change the key for all of them at once so i don't have to switch every single one of them.

An extra menu item in the Tuning Control menu (such as "Assign to all Instruments") or a shortcut would be fine. I guess you could also do it the Song Properties dialog too. (You might want to restrict the function call to only MPTMs.)