The Lightbox Orchestra is an improvising ensemble with a flexible, ever-changing membership, lead by Fredrick Lonberg-Holm. Lonberg-Holm conducts the orchestra with a lightbox and handwritten signs. The lightbox contains a coloured light bulb for each musician which Lonberg-Holm switches on or off to suggest when they should play. During the performance, he also writes a more detailed instructions on pieces of paper, showing them to musicians.