31, is a musical composition for piano by American composer Louis Moreau Gottschalk written from 1857 during a tour in Puerto Rico.
Dedicated to the Dutch piano virtuoso and salon music composer Ernest Henry Lubeck, and published in Mainz circa 1860 with the subtitle of Marche des Gibaros,[1] it is based on the Christmas folk song Si me dan pasteles, denmelos calientes, performed by local peasants known as Jíbaros.
[2] The piece makes use of Latin-American and Afro-American melodies and rhythms almost fifty years before early ragtime and jazz would popularize its use.
[3] Souvenir de Porto Rico was written in the last trimester of 1857, when of Gottschalk's stay at the sugar plantation of English-born Mr. Cornelius Cartwright, in Plazuela.
'"[5] The piece in E♭ minor, set in two-four time with an initial tempo of Moderato ma con moto, consists of a repetition of two specific themes.