Charles Rosen

Charles Rosen, who has died aged 85, was one of America's greatest pianists and writers on music, whose books equalled his piano playing in their authority and verve. Though the piano playing came first – he entered the Juilliard School when he was seven and by 1938 was being taught by the illustrious Moriz Rosenthal – he became in his middle years an author of the choicest, most fearless and vivacious sort.

A specialist in the most enlightening sense of the word, he performed Bach's Art of Fugue as communicatively as Beethoven's Hammerklavier sonata, and Chopin's short piano pieces as lucidly as the shortest of Schoenberg's. Moreover he proved he could write about these works with an eloquence that rivalled his playing of them.

The fact that, as a renowned virtuoso with Liszt at his fingertips, he championed modern composers – none of them more challenging than his compatriot Elliott Carter – spoke for his breadth of musical vision. Few of his major contemporaries showed any interest in doing so. His appearances in Scotland may have been limited to familiar fare but they were notable for the integrity he brought to everything he touched, whether it was Beethoven's Fourth Piano Concerto with the Scottish National Orchestra at a Glasgow prom conducted by Aaron Copland in 1967, or the masterly, rarely heard original version of Schumann's C major Fantasy at the Queen's Hall during the Edinburgh Festival a decade or so later.

These works were performed with the scholarship and finesse for which he was famed, just as his most popular book, The Classical Style, soon established itself internationally as the best of its kind. Dating from 1971, it is now a classic, notable for its quickfire assertion that "the classical style appears inevitable only after the event", and its dismissal of ETA Hoffmann's belief that listening to Haydn was like taking a walk in the country – "a sentiment destined to make anyone smile today".

Born in New York, he became the acme of metropolitan excellence, particularly when lecturing at the keyboard about music which he played to perfection. His frequent essays in the fortnightly New York Review of Books were collector's items, and though his own most recent book, the 438-page Freedom and the Arts, reviewed in these pages last summer, carried a faint whiff of finality, it seemed unwise to speculate at the time that it might turn out to be his last. His range of interests, which from an early age included literature (and French literature at that) as well as music, looked endless.

Adamant that Mozart should never be staged in a theatre with more than 700 seats, he knew perfectly well that this was unlikely to happen unless a tiny company was doing the staging, but he also knew he was absolutely right to make a case for it, since Mozart, when performed well in a small theatre is something as close to perfection as we shall ever get.

Though latterly he walked with a stick and wore a hearing aid, his writing remained as spry as ever and as recently as last year he crossed the Atlantic to give a Chopin recital in London – it might just as easily have been a programme of Boulez – and a few months ago he received America's National Humanities Medal from President Barack Obama in the White House for his service to the arts.

Frail though he looked, he was presumably still writing furiously about all the musical atrocities that irked him, such as Gluck's failure to remedy a personal defect – his lack of contrapuntal technique – which "would have needed no more than a year's study to bring him up to snuff", or the shortcomings of The New Grove, which included an essay on Verdi by an admirable critic who got important matters of harmony surprisingly wrong.

Yet Rosen was himself the most admirable of critics. He did not set out to score points, as many of the rest of us are prone to do. Corrections were made because they were necessary, and misconceptions derided because someone had to do so and Rosen was a writer who could do it aphoristically. Far from sneering at Chopin, as some critics still do, he hailed him as "one of the most radical composers of his age, the belief that he was just a miniaturist pretty much obsolete, exploded, discredited".

As a pianist, Rosen will be missed by all who heard him. But as a writer he will live on, his books, whether as long as The Romantic Generation (1995) or as short as Piano Notes (2002) or Music and Sentiment (2010), glorious models of wit and knowledge.