I think the only way you can really play the same thing the same way each time is if its a CD or tape that you're playing.

Somewhere, I can't remember where so I can't verify this, I heard that shawms used to be used to sound warnings in medieval towns. Particular tunes would be used to indicate particular disasters. I can imagine the scene should a designated shawms player start improvising on those melodies. "Run for Cover its a flood!, no wait a minute there's a bull loose in the market, or is the church on fire?"