Changing the default order of my soundcards

Can anybody, in very simple terms, tell me how to change the priority order, or default order of my soundcards. I have an onboard card, which is disable, at 0, a webcam at 1 and a Sound Blaster Audigy at 2. Ideally, I think, I would like them the opposite way around. I'm trying to use the MuseScore app and I think it keeps trying to use the wrong sound module. I'm getting very a poor quality sound. If I use another app and then go back to it, it has corrected itself and is OK. Next time I boot up - back to poor sound. Anybody any ideas? (Be gentle with me).
Thank you in anticipation.
Phil J.