"Il Barbiere di Siviglia" is an opera composed by Gioachino Rossini, first performed in 1816. The story is based on a play by Pierre Beaumarchais and follows the clever barber, Figaro, as he helps the young Count Almaviva win the heart of Rosina, a beautiful ward of the old doctor Bartolo. The opera is known for its lively music and humorous plot, featuring famous arias like "Largo al factotum." It explores themes of love, deception, and social class, making it a beloved classic in the operatic repertoire.