Sing for simoleons

You don't need a mod for this, Vini. There is an option to sing or play an instrument for tips with City Living. You simply need to first practice your Sim's singing skill as much as possible so you actually will sound good and then after that just go to that community plaza where all the events are held in the city, once you arrived there should be like a small set up around there somewhere that works kind of like a street performer area. Try that first, if this is not what you meant by "Singing for Simoleons." then let me know and I will see what I can find on the web for you. Good luck!