Vi and Va Birthday Celebration

Vi and Va, the two gorgeous dolly sisters, are celebrating their birthdays today, you know, and they'd really like to impress all their friends with a super fum, nonetheless stylish party! Their cousins have agreed to help them with the preparation, would you agree, too, to lend them a helping hand, so that they can have the special surprise birthday song, the yummy birthday cake, the stereo they'll use for playing music and the room nicely decorated right before the guests start to arrive?