We hear two tunes (aka “Hobby” on the Silva Screen CD) - last chaotic bit?
1) Fiddle and flutes (by Giovanni)
2) Once inside courtyard familiar sword dance tune on fiddle (Ten Penny Bit - traditional)
3) and then musical chaos before Summerisle's speech.
Cinefantastique article - "There's a little bit of an electric guitar in the sequence where the villagers all play tricks on Howie, and the hide-and-seek with the Hobby Horse, but we play a lot of Scottish jigs against it, and it works a lot better."
Ten Penny Bit is also often used as the music for longsword dancing in U.S. and is a popular Ceilidh tune in the UK.