Sonata para guitarra (Sonata No.1) was written by Carlos Guastavino (1912-2000) in 1967 and become recognized as one of the major 20th Century full sonatas for guitar. Guastavino was one of the foremost Argentine composers of the 20th century having composed over 500 works, many of them songs for piano and voice but also three sonatas for guitar. The first sonata contains three movements: I. Allegro deciso e molto rítmico, II. Andante, III. Allegro espiritoso.
Recommended Recording: 20th Century Guitar Sonatas by Michael Kolk
Sheet Music: To my knowledge the only edition available is for all three sonatas “Sonatas: para guitarta” published by Melos Ediciones Musicales which you can order from stores or here on Amazon. There used to be a Recordi edition but I can’t locate it at this time. University libraries might have it.
Here’s a nice write up via this Naxos album:
Carlos Guastavino was born in 1912 in Santa Fe, then a small city of about fifty thousand inhabitants. His father had intended his son to be a chemist, before he became aware of his early skill as a pianist, when he sent Guastavino to a German teacher, learning music before he could write. At the age of twenty Guastavino went to Buenos Aires, where he met Athos Palma, a great teacher and person, developing with him his very characteristic talents and his feeling for the music of Argentina. His Sonata No. 1 was written in 1967 and dedicated to his brother José Amadeo. His original idea had been to dedicate it to the Argentinian guitarist Roberto Lara, but when he was finishing writing the first movement, his brother committed suicide, perhaps as the result of a serious illness. Shocked by the news, he returned to his composition to make the second movement an elegy for his brother, who played the guitar as an amateur and used to improvise on traditional Argentinian melodies.
Julia Trintschuk plays the first two movements of Sonata No. 1 by Carlos Guastavino. This comes via Siccas Guitars and their YouTube.
Here are two videos of the entire Sonata, the first one by Eduardo Fernández via Boston Guitar Fest on their YouTube, and the other one of Daniel Bolshoy via the Classical Guitar Society of Calgary on their YouTube.