With his 9th piano concerto, composed in 1777, Mozart entered a new world. The traditional long orchestral introduction is dispensed with, and the soloist enters after the second bar. Nothing as audacious as this would happen in a concerto until Beethoven's 4th, where the soloist starts the work. Performed by Elizabeth Sombart and the Royal Philharmonic Orchestra led by Pierre Vallet, the 9th is a large-scale concerto running over 30 minutes in length. By contrast, the group of three concertos composed in 1782 are less demanding, for both soloist and the listener.