We seldom think of Sir Arthur Sullivan alone. We seldom see his name in the splendid isolation it enjoys on the title page of this definitive biography. The name seems destined to be linked through the ages, as it was in his lifetime, to that of W. S. Gilbert. We remember the names in a Siamese-twin linkage, and if we would be honest most of the nonspecialists (or nonfanatics) among us might confess to trouble remembering which one did the music for The Mikado, The Gondoliers and Trial By Jury, which did the words.

Sir Arthur Sullivan, Victorian musician, expected better of posterity, whether or not he deserved it. When the names of collaborators in musical theater are amalgamated, (Rodgers and Hammerstein, Strauss and Hofmannsthal), the composer can hope to come first. In opera, usually, he stands alone; where are the posters that trumpet the glory of "Piave and Verdi" or "Da Ponte and Mozart"?

Sullivan's fate is not entirely unjust. Our memories from the Gilbert and Sullivan operas (both men resisted the diminutive term "operetta") tend to be as much verbal as musical -- mostly the self-destructive confessions of a ruler of the Queen's Navy, a modern major general or a Lord High Executioner. Or a happy turn of phrase such as "What, never?" "Well, hardly ever." Or a logical conundrum, an absurd situation, a pretty fix.

But when we spontaneously sing Sullivan's music, as in the chorus beloved with the spurious words, "Hail, hail, the gang's all here," perhaps we should remember that he composed it, as he did "Onward, Christian Soldiers" and "The Lost Chord" -- durable little bits of Victoriana in which he had no help from Gilbert.

Serious or comic, Sullivan (the son of a military bandmaster and a bit of a child prodigy) was generally recognized as the leading English composer of his time: "the only English composer we have who has made his mark in what he has done, and who might. . . possibly leave behind him a great name and really great works." As an 18-year-old music student in Leipzig, he made an impression on such famous composers as Liszt and Schumann; later, he enjoyed the respect of Rossini and Gounod. He hoped to be remembered for such works as his Irish Symphony, his In Memoriam Overture and his serious opera Ivanhoe.

The problem (Sullivan's, not ours) is that Gilbert and Sullivan enjoyed, artistically, as perfect a symbiosis as any wordsmith and tunesmith have ever achieved. Gilbert produced texts that may still be read for enjoyment without the music, and Sullivan produced settings that give the words added point and vitality. With impresario Richard D'Oyly Carte, they formed a trio that brought in lavish financial rewards for their joint efforts -- fortunately for Sullivan, who (though a confirmed bachelor) had expensive tastes in living accommodations, travel, gambling and mistresses.

The near-perfect harmony of Gilbert and Sullivan's artistic work was not reflected in their personal relations. Sullivan, his mind on higher pursuits, often became uncomfortable with his international reputation as a comic composer. He harassed Gilbert frequently for a more serious text than Patience or The Gondoliers, and when Gilbert declined, he finally turned to one Julian Sturgis for the libretto of Ivanhoe. Today, it seems that Gilbert was right; Sullivan's genius, like the spirit of his time and place (in Thackeray, Trollope, Dickens, Wilde), was essentially comic. He inclined to easy sentimentality when he became serious, and his longer works tend to become episodic. Gilbert's words provided the most congenial kind of inspiration for his natural talent and the structural framework he needed for works of long duration and long memorability.

Sullivan was, chronically, the instigator of friction between the two collaborators. He was the one with ideas of grandeur, the one who felt that his talent was being wasted or sacrificed on such trivialities as Iolanthe and The Sorcerer. In his diary for Jan. 9, 1889, when their collaboration was nearing its end, he provides a digest of one such discussion: "I explained that I wanted to do some dramatic work on a larger musical scale, and that of course I should like to do it with him if he would, but that the music must occupy a more important position than in our other pieces -- that I wished to get rid of the strongly marked rhythm, and rhymed couplets, and have words that would give a chance of developing musical effects. Also that I wanted a voice in the musical construction of the libretto."

Gilbert, always accommodating, finally rebelled and even began a lawsuit while Sullivan was working on Ivanhoe. But even then, his attack was directed not at Sullivan but at Carte, and the subject was not artistic; it was an insignificant financial quibble about the cost of replacing carpets in the Savoy Theatre. By that time, at any rate, their joint inspiration had begun to peter out; they would collaborate again, but their last two works, Utopia Limited and The Grand Duke, did not have the quality or the popularity of their previous masterpieces.

Sullivan, even apart from Gilbert, has not exactly been neglected by biographers and commentators, but we have not yet seen and are not likely to see a study as thorough, frank, sound in its musical judgments and well-written as Jacobs'. He has made a detailed, new study of the source material, including the diaries, which were not fully available to earlier scholars. Arthur Sullivan: A Victorian Musician is a distinguished profile not only of its subject but of the era that he typified a bit more than he wished to.