The concerto was a popular form during the Classical period (roughly 1750-1800). It had three movements – the two fast outer movements and a slow lyrical middle movement.
The Classical concerto introduced the cadenza, a brilliant dramatic solo passage where the soloist plays and the orchestra pauses and remains silent.
Mozart wrote 21 concertos for piano as well as concertos for violin, French horn, clarinet, and flute. Another famous Classical concerto is Haydn’s Trumpet Concerto in E flat.
The first movement of Mozart’s Piano Concerto No.20 in D minor has a cadenza passage that demonstrates the musical attributes of the cadenza.