Hans Werner Henze's output is primarily dominated by large-scale, representative musical genres with a richly differentiated instrumental tonal palette: opera and other forms of musical theatre works, ballet, solo concertos and cantatas and also music for large-scale orchestra or chamber ensemble. In contrast, the chamber music works which Henze has composed throughout his entire compositional career right up to the present day have always remained somewhat on the sidelines. Many of these chamber music works had been composed for specific occasions, chiefly to honour figures who had accompanied him on longer or shorter stretches of his journey through life.

Henze composed An Brenton in July 1993 for an event commemorating the Australian violinist Brenton Langbein who had just died. The violinist had been a long-standing leader of the Collegium Musicum Zurich, the orchestra established and conducted by Paul Sacher, and was subsequently also the leader of the Basel Chamber Orchestra [Basler Kammerorchester].He additionally held a violin class at the Music Academy in Basel for a substantial period of his career. Interestingly enough, this piece is not composed for the violinist's instrument, but instead for solo viola. The work was given its first performance on 15 July 1993 by Jurg Dahler, one of the two viola players of the Chamber Musicians of Zurich [KammermusikerZurich]. This ensemble had been formed by Langbein in 1962: it frequently included compositions by Henze in its programmes and had given the premiere of Henze's music for Volker Schlondorffs Film Der junge Torless in its transformation as the Fantasia of the same name for string sextet (1967) in 1968. Langbein was the soloist in the first performance of Henze's Violin Concerto No. 2 in 1972 which had been commissioned by Paul Sacher. Henze had already made acquaintance with Langbein during the 1960s.

Hans Werner Henze has composed several film scores for Volker Schlondorff's literary adaptations. 'In 1966 I wrote the music of Volker Schlondorff's first film Der junge Torless. I then thought the sound of the old early instruments that I chose could be understood as a metaphor for the early immature, almost childishly youthful and endangered of the protagonists of Musil's novella. Later I arranged several pieces from the score for string sextet and even made a string orchestra version of it.' (Hans Werner Henze).

My idea of developing music from Richard of Gloucester's monologue 'Now is the winter of our discontent', and of generating more music from that material, was conceived during the 1960s. Ten years later it took a more concrete form, when Julian Bream suggested to me that I should write a substanial new guitar work for him. More time went by, and only having finished 'We Come to the River' could I begin to realise our plan. Then began a collaboration with the instrumentalist that went through various phases, from which I gained a more profound knowledge of the technicalities and of the sound-world of the guitar. I would even go so far as to say that this collaboration gave me a new concept of how to write for an instrument with a rich tradition. The guitar is a 'knowing' or 'knowledgeable' instrument, with many limitations but also many unexplored spaces and depths within these limits. It possesses a richness of sound capable of embracing everything one might find in a gigantic contemporary orchestra. but one has to start from silence in order to notice this: one has to pause, and completely exclude noise.
The dramatis personae of this piece enter through the sound of the guitar as if it were curtain. Through masks, voices and gestures, they speak to us of great passion, of tenderness, sadness and comedy: strange events in people's lives. Into this, the whispering voices of spirits are mingled. The epilogue is spoken by Oberon, pacified and reconciled, as though Nature had been subjected to Man.
- Hans Werner Henze.