The bizarre world of a puritan at the piano by Kevin Bazzana

Like Elvis and Princess Diana, Glenn Gould enjoys ever-increasing posthumous fame. Since he spent his last two decades as a recluse, the pianist's premature physical death barely registered in the public mind. So it makes sense that Kevin Bazzana should begin his book with the afterlife - the homage by composers, novelists, and film-makers, the trade in relics - and an explanation of why this egregious musician should still seem prophetic today.

"Pianist" was in Gould's vocabulary a pejorative term; even "musician" was too limited for his philosophical stance. This was underpinned by contradictory convictions: music existed primarily in the mind, yet clarity of sound was paramount; the interpreter should be the ultimate authority, and at the same time recede into quasi-medieval anonymity. Bazzana has shown elsewhere how these "inconsistencies" fuelled a radical assault on the classical status quo. In an age where -"fidelity" is the highest virtue, "romantic" interpretations are needed as never before.

Gould's idiosyncratic art is, in essence, a return to the music-making of people like Busoni and Paderewski. Yet in the studio he behaved like the musical equivalent of a film actor, while his "contrapuntal radio" programmes anticipated post-modernism. Classical music never threw up a more complicated beast.

This gracefully-written book is the biography Gould fans have been waiting for. Neither his personality nor his genius is "explained", but their emergence is delineated with insight and skill. Born in 1932, Gould was a product of bourgeois Toronto: a reticent boy who internalised the prohibitions of a repressed city, happy to describe himself as the last puritan.

Whether by Byrd or Berg, the music Gould admired was rational, abstract, introspective. The music he didn't like was sensual, self-aggrandising and stained with "worldly grime" (as he said of Scarlatti). For Gould, art was an instrument of salvation.

The piano was his Shangri-La, with the piano-chair his father made for him carried round the world like a metaphorical blue blanket. The posture in which Gould liked to play, with the chair so low he was almost sitting on the floor, still astonishes, as do his histrionic accompaniments: humming and clucking, stamping his feet. These mannerisms, which developed into crazy stage antics, both drew the crowd and led him to turn his back on the whole thing as "vaudevillian". Bazzana's achievement is to show how the quality of his music validated such aberrations.

Was Gould mad? Bazzana judiciously examines the facts - including the friendly pat on the shoulder by a Steinway employee which led Gould to sue the company for grievous bodily harm - and gives a qualified "yes". Was he gay? After carefully sifting the evidence: "no". His hypochondria was legendary, but his obsession with his hands (no handshakes) more practical than neurotic. Those magic mits had to work the miracles we now savour on CD.

Michael Church