Our Very First Telethon - S3-E24
Corrected entry: When Danny is sleeping, Stephanie wants to perform her dance, so she goes and gets her tape. When she starts to dance, we can hear it's a tape (because it's the real singer who is singing), but when she is finished, it's the band who is playing the song.
Correction: Yes, she does use the tape during the actual dance, then because of the way the tape abruptly ends on "Love Shack, " the band plays to segue out of the segment.