To the work of criticism, Mr. Porter brought a formidable training in music performance (he was an accomplished organist); a deft linguistic ability (he translated the librettos of dozens of operas from the original French, German and Italian into highly regarded English versions); a deep knowledge of music theory, music history and composers’ biographies; a keen attention to the historical context in which a work was composed or performed, and to the prevailing political winds, both musical and non-, during those times; a ready command of the entire production history of an opera or the publication history of a score (he was an occasional opera stage director); the abilities of an intellectual gumshoe (he made a major discovery involving Verdi’s “Don Carlos” that altered the way the opera is understood); an acute sensitivity to the architectural and acoustic qualities of concert halls; a robust cultural understanding of the city in which that hall was located; an appreciation of the ways in which music dovetailed with allied arts (he wrote a good deal of dance criticism early in his career); a phonetician’s familiarity with the vowel sounds of a given language, and how they rendered the words of that language more or less singable; a passion for fealty to a composer’s historical intent that was matched by a commitment to the work of 20th-century composers; and much else.

His prose itself was often described as musical, and he had a lexicographer’s command of the language on which to draw. Reviewing “A Musical Season,” one of several anthologies of Mr. Porter’s work, in The New York Times Book Review in 1974, the music critic John Yohalem wrote approvingly, “In a field that tends to strain verbal resources — there are just so many ways to describe a beautiful sound — Porter uses a vocabulary so wide it would do credit to a pornographer.”

Mr. Porter’s critical enthusiasms centered demonstrably on vocal music, and more demonstrably still on opera. This stance caused his critics to charge that for him, all music was vocal music — an accusation he parried in characteristic style in the opening paragraph of a New Yorker review from 1975:

“Anonymous letters I throw into the wastepaper basket without a second glance,” he wrote. “But a phrase of complaint from one of them recurs to me now: ‘Singers, singers, singers!’ It came from a correspondent unwilling to accept that most music is vocal music, and that most writing about music reflects the fact. There was a time, earlier this century, when youth was taught to regard sung music as somehow inferior to the ‘real thing,’ the ‘pure’ music of orchestra or string quartet. That was before Bach’s cantatas, Haydn’s and Handel’s and Monteverdi’s operas, and in general the music of the 17th, 16th, 15th and earlier centuries, became part of the living repertory.”

Mr. Porter’s paragraph continues for about four times again the length of the extract quoted here.

Andrew Brian Porter was born in Cape Town on Aug. 26, 1928; his father was a dentist, his mother a homemaker. He studied music at Diocesan College in Cape Town before taking a degree from University College, Oxford, where he studied music and English.

Mr. Porter wrote criticism for The Manchester Guardian and later for The Financial Times, from which he was plucked by William Shawn, then The New Yorker’s editor, for a year’s trial at the magazine. He remained for nearly 20.