Barbie Voice Changing Rockstar Boombox Sing to built-in music Sing to anything from your own playlist via the MP3 line-in jack Fun voice-changing effect lets girls' voices sound deep, high-pitched like a chipmunk or like a robot Cheering/applause, comments from barbie and vocal music balance Rock out with the included microphone, add a second microphone (not included) to sing duets with friends