Music for a Red Carpet Event
If your red carpet event is not an Oscar night viewing party, you could go all out and hire a brass band or "big band" group for the red carpet entry, and have the band entertain throughout the actual party. Be sure the venue has ample space for a dance floor.
If your party is for watching the Oscars broadcast, you won't need music once the show starts, so you don't really need live performances. You can save money and emphasize the Oscar theme by playing movie theme songs over speakers placed along the red carpet.