Largest busk (multiple venues)

According to Official Guinness Records,

The largest busk at multiple venues consists of 871 participants and was achieved by Musequality (UK) at 21 venues across the world on 11 June 2014.

For a complete list of 2014 records, please visit 2014 Guinness Records in Australia.

Other Australia records that might interest you:

• Fastest time to complete a marathon on each continent, aggregate (male)
• Longest duration holding a 500 kg weight with shoulders
• Tricks, barefoot waterskiing – women
• Most rolls consecutively by an aircraft
• Most couples to participate in a dating event in 12 hours