A concerto is a work composed for one or more instrumental
soloists and a full orchestra.
Concerti (the proper plural), which have three contrasting
movements, have been written for most instruments, including
piano, trumpet, violin, cello, and flute.
Italian composer Antonio Vivaldi (1678-1741) set the standard
for the classical concerto using one soloist and a fast-slow-fast
pattern of movements.