The London Improvisers Orchestra

Since 1997, this sprawling collective has met on the first Sunday of every month. Composers and performers are selected anew each time to create and rehearse a new piece of music during the day, then perform it in the evening. The ever-changing line-up – anything from 12 to 40 musicians – often includes the likes of Ian Smith, Roland Ramanam, Alan Tomlinson, Robert Jarvis, Neil Metcalfe, Terry Day and Evan Parker, among many others.