A concerto is a piece of classical music that features a soloist accompanied by an orchestra or other ensemble. The soloist stands or sits at the front of the stage near the conductor so that they can be seen and heard clearly. Concertos are usually very difficult for the soloist and require technical and expressive expertise. The word "concerto" comes from the Italian word "concertare," which means to work together or to compete. The typical structure of a concerto is a three-movement structure, with a slow movement preceded and followed by fast movements, which became a standard from the early 18th century.

Concertos can be written for one or more soloists, and the soloist(s) and orchestra are related to each other by alternation, competition, and combination. The form of a concerto can vary, but it typically consists of several contrasting movements integrated tonally and often thematically. The most popular concertos are for violin or piano, but there are concertos for every instrument. Some of the most famous concertos include Tchaikovsky’s Piano Concerto no. 1, Beethoven’s Violin Concerto, Dvorak’s Cello Concerto, Mendelssohn’s Violin Concerto, Rachmaninoff’s Piano Concertos nos. 2 and 3, and Vivaldi’s Four Seasons.

In summary, a concerto is a musical composition that features a soloist accompanied by an orchestra or other ensemble. The soloist and orchestra are related to each other by alternation, competition, and combination, and the form of a concerto can vary. Concertos are usually very difficult for the soloist and require technical and expressive expertise.