Keller was born into a wealthy and culturally well-connected Jewish family in Vienna, and as a boy was taught by the same Oskar Adler who had, decades earlier, been Arnold Schoenberg's boyhood friend and first teacher. He also came to know the composer and performer Franz Schmidt, but was never a formal pupil. In 1938 the Anschluss forced Keller to flee to London (where he had relatives), and in the years that followed he became a prominent and influential figure in the UK's musical and music-critical life. Initially active as a violinist and violist, he soon found his niche as a highly prolific and provocative writer on music as well as an influential teacher, lecturer, broadcaster and coach.
An original thinker never afraid of controversy, Keller's passionate support of composers whose work he saw as under-valued or insufficiently understood made him a tireless advocate of Benjamin Britten and Arnold Schoenberg as well as an illuminating analyst of figures such as Mozart, Haydn, Beethoven and Mendelssohn. Many of Keller's earliest articles appeared in the journals Music Review and Music Survey -- the latter co-edited by him after he joined the founding editor Donald Mitchell for the so-called 'New Series' (1949-52). In later years, much of his advocacy was carried out from within the BBC, where he came to hold several senior positions. It was also from within the BBC that Keller (assisted by Susan Bradshaw) perpetrated in 1961 the famous 'Piotr Zak' hoax, designed to demonstrate the poor quality of critical discourse surrounding contemporary music at a problematic stage in its historical development. In 1967, he had a famous encounter with the rock group Pink Floyd (then called 'The Pink Floyd') on the TV show
The Look of the Week. During the interview, Keller is quoted saying that Pink Floyd's music was "...a little bit of a regression towards childhood".
Keller's gift for systematic thinking, allied to his philosophical and psycho-analytic knowledge, bore fruit in the method of 'Wordless Functional Analysis' (abbreviated by the football-loving Keller as 'FA'), designed to furnish incontrovertibly audible demonstrations of a masterwork's 'all-embracing background unity'. This method was developed in tandem with a 'Theory of Music' which explicitly considered musical structure from the point of view of
listener expectations; the 'meaningful contradiction' of expected 'background' by unexpectable 'foreground' was seen as generating a work's expressive content. An element of Keller's theory of unity was the 'Principle of Reversed and Postponed Antecedents and Consequents', which has not been widely adopted. His term 'homotonality', however, has proved useful to musicologists in several fields.
Keller was married to the artist Milein Cosman, whose drawings illustrated some of his work.
As a man very prominent in the world of 'contemporary music' (even working for several years as the BBC's 'Chief Assistant, New Music'), Keller had close personal and professional ties with many composers, and was frequently the dedicatee of new compositions. Those who dedicated works to him include:
- Benjamin Britten (String Quartet No.3, Op. 94)
- Benjamin Frankel (String Quartet No.5, Op.43)
- Philip Grange
- David Matthews (Piano Trio No.1; 'To Hans Keller')
- Bayan Northcott
- Buxton Orr (Piano Trio No.1; 'In admiration and friendship'),
- Robert Simpson (Symphony No.7; 'To Hans and Milein Keller').
- Josef Tal (Double Concerto for Two Pianos and Orchestra; 'To Hans and Milein Keller')
- Robert Matthew-Walker (Piano Sonata No.3 - 'Fantasy-Sonata: Hamlet'), Op.34 (1980)
In December 1979, Keller received the 'Special Award' of the Composers' Guild of Great Britain. In September 1985, just weeks before his death from Motor Neurone Disease, he received from the President of Austria the
Ehrenkreuz für Wissenschaft und Kunst, 1 Klasse ('Cross of Honour for Arts and Sciences, 1st Class').
