This week, somewhere around Melbourne, a symphony is going to materialise. No one can rightly say when or where, but the Melbourne Symphony Orchestra will be rocking up in an unexpected spot in the city.

Dreamed up by the MSO’s artistic team, Huw Humphreys, Anna Melville along with Andrew Pogson, Secret Symphony is a regular pop-up performance that’s always unpredictable.

The idea is simple: music-lovers follow the MSO’s Twitter feed - @asecretsymphony - and 24 hours before the show, they drop the news on the location. The repertoire, however, remains confidential until the tunes start.

Previous Secret Symphonies have included orchestral renditions of Radiohead and Steve Reich’s Different Trains performed underneath Flinders Street Station, a performance at Melbourne Gaol, and Bond themes at ACMI.

And while we can’t divulge the whereabouts of this week’s Secret Symphony, if you keep your ear to the ground (and your Twitter feed), you might find a few clues.

Follow MSO’s Facebook page or Twitter feed for more details.