The vast output of Italian-Spanish composer Luigi Boccherini, contemporary of Haydn and Mozart, remains little explored, and each time a fully realized album of his works appears it suggests great unknown riches. This release by Spain's Cuarteto Casals, with cellist Eckart Runge and guitarist Carles Trepat, is a case in point. Two of the works are popular in excerpts: the String Quintet in C major, Op. 30/6, whose march finale "La Ritirata de Madrid" is often played, and the String Quintet in E major, Op. 11/5, with its ethereal little minuet. But both of these movements are stronger when placed within the full works, and the C major quintet, entitled "La musica notturna delle strade di Madrid" (Night Music of the Streets of Madrid), is exceptionally well performed here. As the title suggests, this seven-movement quintet, for the characteristic Boccherini combination of two violins, viola, and two cellos, is programmatic; what you may not be ready for is how detailed it is and how freely it treats the basic Classical style. You know you're in for something fresh with the opening strummed chords, and the Cuarteto Casals plays the entire thing to the hilt. The seven sections depict church bells, drum rolls from a military barracks, a "minuet of the blind beggars" in which the cellists have to play their instruments like guitars, a rosary prayer, street singers, another drum roll, and the "ritirata" finale. The other two works are equally attractive; the String Quartet in G minor, Op. 32/5, demonstrates that Boccherini could write very well in the serious Haydn mode when he chose to, and the finale, the Guitar Quintet in D major, G. 448, consists of works in other media transferred to a brilliant flamenco-inspired setting. It's hard to think of a Boccherini release that offers more sheer fun than this one.