Practical Music? Purpose Music?

I have been lately composing music for the church calendar - at the moment music for the Advent season. It has opened up a little thing for me I have often thought about - writing music which has a function inside the culture. Not Gebrauchsmusik (shudder), but music which which fulfills a purpose. Purpose Music sounds nice. Writing music for parties, or for film, or for church services or music which is part of the whole. Of course, nothing is wrong with "concert" music, but sometimes I find this strangely detached from my life.

I certainly don't want to write "elevator music" or "shopping music", but then again, why not? I also don't want to be John Williams (except for the money part!) I don't want to write "ordinary" elvator music. "Music for Airports" by Brian Eno is an excellent example of Purpose - even though the Purpose has been taken away by the passing years.