PekeSims found in The Sims 4 CAS Demo’s game files 8 different soundtracks/layers of The Sims 4 CAS Music! This approach of layered music should be applied to other game modes as well.
This fansite also found some other Sound effects which are available for Download from her site.
Click on the picture below to download CAS Music/Sound Effects from PekeSims!
Site is down, anyone else got a direct download?
Link is dead
Here’s an updated link:
http://www.google.com/translate?hl=en&sl=auto&tl=en&u=http%3A%2F%2Fpekesims.com%2Fdescargas%2Fls4%2Fdescarga-la-musica-del-cas-de-los-sims-4&sandbox=1