1, commonly referred to by its original Italian name Sonata per archi, is a composition for string orchestra by German composer Hans Werner Henze.
The sonata was commissioned by Paul Sacher for his own orchestra, the Collegium Musicum Zürich, together with his Double Concerto for Oboe, Harp and Strings, and was written between 1957 and early 1958.
The movement list is as follows: Its structure is nothing like a traditional sonata and displays the composer's distinctive serialist style.
The first movement consists of a five-minute Stravinskian toccata, with plenty neo-classical features.
The second movement is presumably influenced by Beethoven and consists of a set of attacca variations which are very difficult to distinguish by ear.