The Boléro, Op. 19, was written by Frédéric Chopin in 1833 and published the following year. It is one of his lesser-known piano pieces, although it has been recorded numerous times.
The overall key of the Boléro is difficult to establish. It was often listed as Boléro in C major - A minor, as the work opens with three unison octaves in G (dominant chords of C major) in fortissimo, then a lengthy Introduction in C major, moving to A minor for the Boléro proper. It is interrupted by sections in A major, A-flat major and B-flat minor before returning to A minor. It ends triumphantly in A major (parallel major).
The work was dedicated to the Scottish-born but half-French Mademoiselle la Comtesse Émilie de Flahaut, then aged only 14. She was later to become Countess of Shelburne.
The apparent inspiration for the Boléro was Chopin's friendship with the French soprano Pauline Viardot, whose father, the famed Spanish tenor Manuel García, had introduced boleros to Paris by the time of Chopin's arrival there. His biographer Frederick Niecks speculated that it was inspired by the Bolero in Daniel Auber's La muette de Portici (1828).
Despite the ostensibly Spanish flavour of the piece, it has been described as a polonaise in disguise, or a boléro à la polonaise, as its rhythms are more redolent of the national dance of Chopin's homeland than anything Spanish. It was written five years before Chopin first visited Spain (1838). Many people today claim it as the "only Polish Bolero ever written".