I just found out about Pancake Mountain, an all ages music show on cable TV in Washington DC and NYC where they have "dance parties" similar to American Bandstand or Soul Train, but the music is punk rock/indie and kids are under 10. From their site:
Pancake Mountain aims to bring back what got us passionate about music. We want to be able to tear down the barriers that make music pretentious and boring. We enjoy seeing the artist interact with their audience. We like to have fun, we love new music, and we need an excuse to act really silly and call it our job.
Metric - Monster Hospital
The Evens - Vowel Movements
Deerhoof - Spirit Ditties of No Tone