Pam try this:
Get to Central Park right at 7am on a weekend. That's the earliest you can call for a party. Host the party there (obviously). When you hang up, immediately start playing for tips despite the fact that no one has shown up yet. See if that at least gives you a good initial round of tips when everyone shows up. They'll get bored and start dancing eventually — that's to be expected. But, they should show up and throw money at your Rock Star right away.
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EDIT: Ha ha. I just tested this technique and it totally flopped. It has worked before, but for this one test everyone showed up and either started talking or dancing. But, I cancelled the tip playing, started it again, and then everyone locked their attention on him for a good 2 Sim hours and he made around 5k. It does seem to vary quite a bit from session to session. And I'm sure some of it might be how the individual traits of the audience play into things — i.e. how long they'll stand there throwing money before moving onto something else.