The Sonata for guitar, Op. 47 is a composition by Alberto Ginastera. This sonata was written in 1976 for the guitarist Carlos Barbosa-Lima. It's the only original composition for guitar by Ginastera. Ginastera added a few musical "special effects" to the usual sounds of the guitar. The opening "Esordio" is built on two themes: One has the quality of an exhortation, with accompaniment of punctuating chords. The other theme is more lyrical, with percussion effects. The second-movement Scherzo is perhaps the most extreme in its use of unusual sound effects: glissandi of both single notes and chords, strumming on the strings in the area where they are attached to their tuning pegs, and causing the strings to snap against the fingerboard punctuate a rhythmic movement. At times, the rhythm stops for some serious-sounding out-of-tempo statements, which are then interrupted by the scherzo. However, the third movement, the "Canto" is entirely unmeasured, like a flowing, improvised serenade, with frequent changes of tempo and spirit. The final movement is a vigorous rondo, with rhythms that can be traced back to pre-Columbian cultures of the...