Last night marked the Washington debut of 26-year-old Finnish conductor Esa-Pekka Salonen -- a diminutive man with flowing blond locks that make him look more like the king of bubble-gum rock than a master conductor. But it took no more than a few minutes on the podium before the National Symphony to suggest that he may have the makings of a master.

He had the orchestra playing in a way that few of this season's other guest conductors could match. Oddly, it was through one of the best of them, Michael Tilson Thomas, that Salonen, who had never conducted outside Scandinavia, got his big break about a year and a half ago. Tilson Thomas had to cancel for a performance of the awesome Mahler Third with London's Philharmonia Orchestra and Salonen was brought in to sink or swim with it. The reception was rapturous.

For all the authority and imagination Salonen displayed last night, his Kennedy Center program was too esoteric to provide the basis for too broad a generalization about his musical future. He needs to be heard in some basic repertory.

But one thing was unmistakable -- the level at which he had the National Symphony playing. The two most taxing works, Sibelius' "Pohjola's Daughter" and Nielsen's Sympohony No. 4, Op. 29 ("Inextinguishable"), are dramatically explosive early 20th-century compositions of enormous instrumental intricacy. The precision with which Salonen had worked out countless hurdles of balances, attacks, textures, dynamics and general expressive emphasis was remarkable. The music thundered and whispered, but always with impeccable clarity.

Salonen presided with unbroken unflappability, deep in concentration. There is nothing especially theatrical about his efficient manner.

The Nielsen performance -- with its basic dramatic design of turbulance, followed by cataclysm, followed by renewal -- was especially effective. Fred Begun's repeated blasts from the tympany sounded like Armageddon itself and John Martin's bleak solo cello sounded like death itself (as his playing also did in the Sibelius).

The concert opened with an unexpected delicacy from a normally indelicate composer, Luciano Berio. It was a kaleidoscopic reorchestration of Boccherini's "Ritirata notturna di Madrid" in Ivesian 3-D (or, perhaps, 4-D). Webern's brilliant but microscopic Five Pieces, Op. 10, also were played but almost got overwhelmed in the scale of the rest.