Bands could work as an EP if they expanded it beyond rock bands. Introducing a band after school activity, expanded additional instruments like string and brass items. Addition of music festivals your Sims could attend if they are not pursuing a music career. Expand singing career like the acting career. They could have different types of venues to play in like in S3. They could pair it with a highly themed world. They could pair it with more amusement park type things, one of the venues for musicians could be town fairs or carnivals...
Or they could do a gamepack, I'm not opposed to gamepacks.
