Clangers music wheel

[chume14]

Hi so in one of the episodes of the clangers the soup dragon puts music notes on the outside of a wheel and then spins it to play music. I always thought this was on the episode called 'music' but I just watched that episode and it's not so is desperately need to know which episode it is from. For reasons I can't divulge it is extremely important I find out soon so any help would be appreciated thanks.

I put this in fun and games because I thought elsewhere people might get annoyed at it not being a very good topic but here I didn't think anyone would mind :)