Mario Castelnuovo-Tedesco's Les Guitares bien tempérées, Op. 199, for two guitars (1962) is a set, divided into four volumes, of 24 preludes and fugues in all the major and minor keys -- the title translates to English as "The Well-Tempered Guitars," which the musically literate will immediately and rightly read as a take-off on J.S. Bach's seminal and similarly-titled harpsichord work. By 1962, Castelnuovo-Tedesco's musical candle had long been burning rather dimly (though he continued to produce new music quite prolifically), but by combining his deep interest in guitar music with his deep admiration for Bach, he managed, with Les Guitares bien tempérées, to concoct some of his most interesting, if by its very nature perhaps least original, music of the 1960s. The score, like so many of his, remained unpublished until several years after his death in 1968, but has since earned reasonable favor with the world's concert guitarists.
Castelnuovo-Tedesco organizes his 24 preludes and fugues by key, but differently than J.S. Bach does in his Well-Tempered Clavier: starting with G minor, Castelnuovo-Tedesco moves up around the circle of fifths, alternating between the major and minor modes, so that the G minor Prelude and Fugue are followed by the D major Prelude and Fugue, the A minor Prelude and Fugue, the E major Prelude and Fugue, and so on. The composer draws more than the basic concept and format from J.S. Bach's WTC: the ground-level musical operating procedures are for the most part identical as well. In most of the preludes, a basic motivic notion -- a short figuration, arpeggiation, etc. -- is taken up and spun out into a life-giving series of harmonies. The two guitars act more or less as the two hands of a keyboardist (it is clear that a good part of this music was conceived at the piano), and very often, as in Bach's WTC, they take up the basic motivic thought in imitation. Some of the preludes, like No. 5 in B minor, which moves back and forth between Piuttosto mosso e agitato music and a grim funeral march, are multi-sectioned.
The fugues do not hold up well if we are using Bach's as the standard -- Castelnuovo-Tedesco's voice leading is neither strict nor especially graceful, and his subjects do not always lend themselves to high-grade imitation -- but on their own terms they are colorful little bits of contrapuntal action, and the composer knows how to draw a beautifully resonant, frankly irresistible tone from the two instruments.