They all seem to start the same way – a public location – a mall, a public square, an airport, a few people wandering through with purpose, and then it all snaps into focus. The music starts, or the bass player arrives, and we have a flashmob.

One of the most interesting things about the flashmobs, particularly the summer ones, is the variety of people who are passing through, and then turn out to have a violin tucked in their shoulder bag, or there’s a flute, and of course, one goes everywhere with a cello.

The music chosen has to be loud and memorable for the outside performances: Bolero building to its big ending, the Ode to Joy complete with full chorus, an abridged 1812 Overture without cannon but with lots of percussion. Cleaning ladies turn into dancers, airplane pilots join in, and that group of young people up in the balcony turn out to be doing more than just shopping for the day.

Here are a few of our favourites:

Hong Kong Festival Orchestra flashmob at Shatin New Town Plaza in 2013 with Beethoven’s Ode to Joy – keep an eye on that upper floor when everyone turns out to be in the chorus.

The Berklee Contemporary Symphonic Orchestra in 2016 at the Prudential Center, Boston.

When Carmen transforms from a dish washer into a soprano and then walks away…

More Carmen at the Reading Terminal Market in Philadelphia. We love how the last singer goes from ‘inevitable guy on cell phone’ to active participant.

This Nürnberg flashmob has a wonderful interplay between the strolling recorder player and the bass player to start – it just gets bigger and bigger.

The supermarket La Traviata is great fun with the security guard and the cleaning ladies who turn out to be part of the action.

The tenor launches and the woman on the escalator behind him looks alarmed, but what a voice.

Bolero in Copenhagen, at the train station.

These seemed to peak around 2016 but the occasional one can still be found – look around and see what’s happening in public music making where you are!