The Sims Bustin' Out

Try doing this way get malcolm as your friend or best friend (100 freind points) let him eat then ya ask him for the part, see if that would work

Alright here is what you should do. First, be Best Friends with him (100 Relation Points). Second, The room that has a mircophone in it make the room bigger. Thrid, Put a piano in the room that you made bigger. Fourth, Make some some breakfeast, lunch, or dinner(I make Humphery or Fanny make breakfeast, lunch, or dinner). Fifth, Throw a party. Sixth, If Malcolm doesn't come invite him over. Then go and play the piano and go and click Malcolm with the little thinge that you control the sim with and tell him to " watch ".
This should help if it doesn't I'm sorry!! :(
Hope it does help!! :)
!!!!!!Good luck in the sims world!!!!!

Well smokeybowbowkie was right but you can do it this way as well =]
get a hundred friendship points with him, feed him and dance with him to make his moods go up then play the guitar in a well decorated room that makes your home motive go high he might either start clapping or booing if he boos you do it for ages and get your creative/charisma points up i can't remmeber which ones until he starts clapping (it takes time but its worth it) then stop and ask him he should say yes so now you should have a job and have a new best friend! hope this helps apologies to you if it doesn't work :()