Agadoo? Fucking hell I’m in my 40s and that was naff at school discos even in my day (they played Rick Astley, Madonna, NKOTB).
Most boys at primary discos jump around instead of proper dancing. By senior school, they’ve usually perfected the drum&bass arms-folded-nodding-at-the-side-of-the-dancefloor routine. If he wants a better sense of rhythm, send him to a street dance class. But don’t force it on him, plenty of kids never dance at school discos.