MUSIC REVIEW : Flair and Frenzy at the Pavilion : Music: Young Austrian conductor Franz Welser-Most makes his Los Angeles Philharmonic debut with an odd program.

‘Tis the season for promising, young, relatively obscure guest-conductors at the Music Center.

This week’s contender is called Franz Welser-Most. Los Angeles may not think it is a household name, but the big dealers in the international music biz clearly regard the 31-year-old Wunderkind from Austria as a hot property.

In a few short years, he has risen from student-orchestra leadership to a minor post in Germany (Ludwigshafen) and a major one in Britain. He became music director of the London Philharmonic in 1990, and will return with that orchestra to Los Angeles next March.

He already has conducted opera in Vienna, has made records for EMI, and has stood on glamorous podiums in Berlin, Salzburg, Munich and Philadelphia. Debuts in Chicago and Cleveland are in the offing.

His debut with the Los Angeles Philharmonic on Thursday suggested that his sudden success is no fluke. Obviously intelligent and instantly authoritative, Welser-Most isn’t just another product of an overactive hype machine. Nevertheless, it remains to be seen, and heard, if he really is as good as his handlers think he is.

The initial evidence at the Dorothy Chandler Pavilion wasn’t conclusive. Welser-Most chose an oddly constituted program of Mozart, Dohnanyi and Mahler and conducted it with flair that sometimes gave way to frenzy.

When he made his entrance, he looked dour. Here was a blond, slender and bespectacled Clark Kent who happened to carry a baton.

He sustained his mild manner for the seria flourishes of the overture to Mozart’s “Clemenza di Tito” and for the naive charms of Mozart’s D-major Rondo for piano and orchestra (written when the composer was a precocious 17). He flexed his muscles only modestly in the innocent exertions of Dohnanyi’s Nursery Tune Variations.

He assumed the demeanor of a musical Superman, however, when confronted with the grandeur of Mahler’s Symphony No. 1.

Ultimately, he seemed most impressive in the Mozart. Unlike many a young and impetuous colleague, this conductor understands that grace need not preclude urgency, that one can be sensitive without being wimpy. He resisted the temptation to manicure the line with fussy accents, yet always savored the virtues of clarity, poise and propulsion.

Dohnanyi’s essay on the earth-shattering implications of “Twinkle, Twinkle, Little Star”--a.k.a. “Ah! Vous dirai-je mamam”--sounded a little trite, coming right after these exercises in Mozartean elegance. Still, Welser-Most demonstrated an easy aptitude for the pop-concert rhetoric and respect for the satirical undertones.

Jeffrey Kahane, the soloist in both rondos, mustered jaunty finesse for the Mozart and fleet bravado for the Dohnanyi. He avoided the thunderbolts that more aggressive wizards like to throw in Dohnanyi’s flashiest diversions, but this pianist’s amiable discretion made its own kind of sense.

The tone of the concert changed drastically after intermission. In the Mahler First (bereft, as usual, of the “Blumine” movement), Welser-Most got excited. Possibly too excited.

He shifted tempos willfully within tempos. He made the orchestra roar too much one moment and whisper too much the next. Mellowness is not yet his forte.

He let the music sigh, whimper and simper, above and beyond the norm. Occasionally, he dwelled on secondary details at the expense of primary impulses.

Even in moments of lyrical calm, Welser-Most’s Mahler seemed overwrought. In the whomping climaxes, it seemed downright cataclysmic.

One had to admire the young maestro’s heroic perspective and expressive daring. At the same time, one had to worry about interpretive distention and distortion, not to mention orchestral imprecision.

If Welser-Most brings this much agitation to the Mahler First, what will he do when he reaches the Ninth? His progress should be interesting to observe.