A Book of Liszts, By John Spurling

With the Faustian frenzy of the first "Mephisto Waltz" and the macabre extravaganza of the Totentanz, tonight the BBC Proms winds up its celebration of the music of Franz Liszt. Born 200 years ago, the son of a farm manager on the Esterhazy estates in Hungary, the piano virtuoso and revolutionary composer debuted aged nine. At 11, he played for Beethoven, who kissed the boy's forehead and blessed him as "one of the fortunate ones" who bring "joy".

Liszt did not merely define what musical celebrity would mean for the next two centuries. Up to the death in Bayreuth of the silver-locked mystic, guru and icon in 1886, he sketched and executed all the movements in an epic symphony of modern fame. From miraculous prodigy and demon lover to globe-trotting headline act, mid-life recluse, comeback veteran and ageing sage encircled by rival acolytes, Liszt premiered each superstar role.

Ingenious and entertaining, John Spurling's bicentenary book matches its arch-Romantic subject to a suitably hybrid literary form. Rather than attempt another straight biography (and he pays his dues to Alan Walker, who wrote the definitive account), Spurling's bio-fiction spans the keyboard of Liszt's life in 15 polymorphous chapters. Like the composer's variations, they navigate among disparate forms with a sumptuous promiscuity.

First-person sections recall the music, the mistresses (not that many, contrary to legend) and the endless, punishing travels. Liszt dazzled not only in Vienna, Paris and Constantinople but Sunderland, Rochdale, Newark, Chelmsford, Preston, Hull, and so on ad infinitum through Europe.

Beatles-style, he then gave up performance in 1847 to write in peace, first in Weimar –with his consort, Princess Carolyne von Sayn-Wittgenstein - and then at the Villa D'Este outside Rome. Liszt may have been "the first musician to be treated on equal terms by noblemen and monarchs", one worshipped for his "almost supernatural gifts". But he also road-tested all the afflictions of fame, from loopy groupies and creative burn-out to betrayal by scheming disciples – above all, of course, his protégé Wagner, who married Liszt's daughter Cosima after breaking up her marriage to Hans von Bülow.

Other voices enrich the texture, harmonious or dissonant: Liszt's mentor, the reformist priest Lamennais; his fey friend Marie Duplessis, original "Dame aux Camélias"; his long-distance partner, Marie d'Agoult; a Habsburg spy in the guise of Mephistopheles... The author even takes a bow, quarrelling with Liszt over the ethics and aesthetics of a book the composer berates as an "ersatz tissue of fact and fiction".

Literary, autobiographical, programmatic, Liszt's romantic excursions find echoes in Spurling's own "paraphrases" and "reminiscences". So the Années de Pélerinage, the piano suites that chart his outer and inner journeys, become a melange of biographical narrative and storm-tossed Alpine prose-poetry that finds words to match the surging, swirling chords.

This overt "literariness" in Liszt's composition has bemused or even repelled some later musicians and critics. Yet it energises Spurling's semi-fictional cadenzas. He seldom plunges into bathos, in part because the visionary who sought "to make all music a vehicle for the spirit" also embraced – or anyway encountered – enough excess and vulgarity to justify the swerves into farce and melodrama. Ken Russell's notorious film Lisztomania – with The Who's Roger Daltrey as the maniacal ivory-basher – kept a kernel of method in its madness.

As one of Spurling's sprightliest passages reminds us, it was the star courtesan "Lola Montez" (really, Eliza Gilbert from Cork) who introduced her squeeze to von Bülow and so set in train generations of Liszt-Wagner imbroglios, while reducing the Beethoven festival in Bonn to "drunken chaos". Purists and classicists, beware. That episode, like Liszt's zigzag progress in this book, will delight those who enjoy music, and life, not as an even-tempered sequence of orderly transitions but as "a wonderful tangle of circumstances".