This thread over on the EA forum
http://forum.thesims3.com/jforum/posts/list/25487.pageby KLHII said this is what he did to complete the challenge:
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"OK, after allot of trial and error, I figured out how to complete this **** thing, lol.
Accept opportunitys that have you perform at a fund raiser (anything music related you want to grab). I did 3 of these, and the last one (At Bistro's diner) was when I got credit for the star.
DON't:
1) Throwing parties and performing, does not affect it. I did not throw any parties this time around (this was my second sim, I scraped the first guy, since I thought I missed something when trying to get this star).
2) Performing at random locations does not play a role in it. (I have 9 performaces in my guitar journal).
My daily routine was:
1) Head out to the theator, from earlier morning to 3 pm, and play for tips.
2) At 3 pm, I check to see if I can perform at the stadium (sometimes they have other events preventing me from performing there). Otherwise just perform at the theator as many times it will allow before it closes.
3) Head home, eat, sleep, and then repeat above steps.
I sure hope this helps you guys, and it did take a long time to get the star. I just wish EA was a little more clear on it, as the directions go.
Enjoy and Good Luck,"
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I haven't completed this challenge myself, but my rock star did get a few opportunites to play at different venues. My 5 star chef was offered opportunites to play at the diner and bistro. I guess one more thing I need to finish doing...