Tomorrow night, Lorin Maazel begins his third season as music director of the New York Philharmonic. At 74, he is one of the world’s most enduring musical presences. His orchestra seems to love him; his audiences seem to love him; with critics, he seems to have trouble – but critics must not be allowed to tell the whole story.

By any reckoning, Mr. Maazel is a formidable man, a wunderkind – a former wunderkind – an all-purpose conductor, a violinist, a composer. His combination of learning, experience, and talent is hard to beat. He has held sway in Pittsburgh, Cleveland, Vienna, Berlin, and several other places. Next spring, his opera “1984” – based on the Orwell novel, of course – will have its premiere in London. In addition, the Philharmonic will present an all-Maazel concert in March. The conductor will be on the podium; his 75th birthday will be the peg.

The man he replaced, three years ago, was Kurt Masur, who had been music director of the Philharmonic since 1991. Mr. Masur was repeatedly knocked by critics, for being “conservative,” for being “traditional” – basically, for being a stiff. But he had done amazing work, in making the Philharmonic a more disciplined and more musical bunch. This was either unrecognized or dismissed. The cry went out for someone younger, someone “hipper” – that word was actually used: “hip” – and someone American.

Strange about critics: They’d normally not be caught dead uttering a nationalist word, but they become all blood-and-soil-like when it comes to choosing a conductor.

Well, after flirting with some others – most heavily with Italian maestro Riccardo Muti – the Philharmonic chose Mr. Maazel. He was not much younger than Mr. Masur (only a couple of years); he was not considered hip; but he was American, sort of. (Can you imagine anyone more “international” and jet-setty than Lorin Maazel?)

I, for one, was skeptical about his appointment, but certainly not on age/hipness /nationality grounds. I had longstanding musical concerns. I would say snotty things like, “Lorin Maazel has the most beautiful baton technique on earth – and from that baton come some of the earth’s most vexing interpretations.” No doubt, Mr. Maazel can often drive you nuts. But, fortunately, I was wrong about the wisdom of his appointment. He can be an extremely compelling, exciting, fulfilling conductor. This is true even when you’re disagreeing with him. He holds your attention; you want to know what he’ll do next.

Most concerts with him are something of an adventure. A customer can feel he’s getting his money’s worth. And he can know that the conductor is giving his all – he is not phoning in.

Indeed, he may be at his best in works that are thought hackneyed. He does not treat them as hackneyed. When he conducts, say, the Tchaikovsky Fifth Symphony, it is not with an air of, “Oh, this old nag again?” He conducts with the enthusiasm and attention of a youngster getting his first crack at the score. Such freshness is invaluable in a conductor.

And, surely, youthfulness – where it is required – is more important than age. Mr. Maazel can be as peppy as anyone (and plenty of young conductors can be bores, believe me).Moreover, his physical stamina is a continuing wonder. He actually runs – runs – off a stage (though less often on).

Then there is the question of contemporary music: Some believe that he programs too little; others believe that he programs too much. You can’t please everybody, in this business as in any other. The standard, I believe, should be worthiness, not newness for newness’s sake. And balance, a varied menu – that is another standard. I doubt Mr. Maazel disagrees.

This summer, the Philharmonic announced that it had extended his contract to 2009. There is nothing to say they can’t renew it. Some conductors don’t really get warmed up until they approach their 80s. We used to honor age in conducting; we used to consider the sight of gray or white hair reassuring. The urge for youth is rather novel.

In its announcement, the orchestra also said that it would feature prominently three guest conductors. They are Mr. Muti, David Robertson, and Alan Gilbert. This is thought, by some, to set up a kind of competition: Who will be Mr. Maazel’s successor?

Mr. Muti is the most established of these men, another conducting celebrity. He passed up the chance to head the Philharmonic once. Would he change his mind? It has been said that he’s intrigued by the Philharmonic job because it used to be filled by his legendary national forebear, Toscanini.

Mr. Robertson is a darling of the critics, who seem to like his (relative) youth – he’s in his 40s – and his “commitment” to contemporary music and his Californianness. I myself have found him a competent conductor, even if I am sometimes baffled by the hosannas he receives.

Mr. Gilbert is the youngest of the trio, in his late 30s, and he has the advantage – if it is an advantage – of being the son of two Philharmonic musicians. His appointment would produce sweet stories.

If youth is the thing, however, I might suggest Antonio Pappano, now at Covent Garden, who made a smash debut with the Philharmonic last season. But, again, why should youth be the thing? Or nationality? Or anything else unrelated to musical excellence?

As I frequently assert, this is not a great age for conductors. Singers, yes – also violinists, I would argue. But not conductors. This city is lucky to have two outstanding conductors, working on the same plaza (Mr. Maazel and James Levine, of the Metropolitan Opera). I have found fault with Mr. Maazel in the past, and will throughout this season, I’m sure. But he is about as good as it gets these days.

And I have a suggestion for Philharmonic management: When it comes time to decide once more, don’t listen to the critics – necessarily.