Rough, but often compelling, playing at the symphony this week.

A conductor coming to an orchestra for the first time must run a gantlet of competing interests. He has to choose his program without knowing the group, and he wants to be invited back. Try something too challenging or new, and everyone ends up looking bad.

Playing it safe with familiar repertoire invites comparisons with everyone’s favorite conductors, against whom the newcomer is likely to be found wanting. At the National Symphony Orchestra’s subscription concerts this weekend, newcomer John Storgårds will be walking a fine line with a program of two obscure Russian tone poems and two Scandinavian war horses.

Storgårds is a good conductor. He is vigorous and detailed, but it’s all for the players; there’s no showboating, and many times he stepped back and let the music just happen. But he perhaps asked too much with this program. The ending Nielsen Fifth Symphony, one of the hardest in the repertoire, clearly gobbled up so much rehearsal time that the other works all had a seat-of-the-pants quality. The sprawling, noisy, unfamiliar, original version of Mussorgsky’s “Night on Bald Mountain” had the NSO scrambling in spots, and Anatoly Liadov’s gossamer “Enchanted Lake” featured some unfortunate gaffes in the horn section.

In between was the Sibelius Violin Concerto with the distinguished Latvian virtuoso Gidon Kremer, who occupies sort of a cult status in the music world. The artist, in his mid-60s, was classical's first musical omnivore. His interests have encompassed the harshest contemporary works, such gentler souls as Glass, Adams and Pärt, and crossover ephemera from Charlie Chaplin to Gloria Gaynor. He approaches the mainstream repertoire without any sense of tradition, simply going wherever the score and his imagination take him. For decades he was the most interesting violinist before the public.

So it is with sadness that we note a weakening of his once lithe and sinuous playing. He needed to use a score and kept his eyes fixed on the music between solo passages, as though mentally practicing the next one. He “got” everything, but not with the icy mastery of old. For the first time, one felt that what came out was partly a result of technical compromise; the sound was strong overall, but it was inconsistently controlled, and there was some struggle in the passage work. It was a little strange that Storgårds, a fiddler, didn’t keep the orchestra down better, though he successfully allowed musical space for his unpredictable soloist.

Carl Nielsen, one of the 20th century’s great symphonists, remains undervalued. The NSO lays particular claim to Fifth since it gave the U.S. premiere in 1951, almost 30 years after the work was written. Nielsen’s symphonies as a group rival those of Shostakovich or Sibelius, and surpass those of Vaughn-Williams, Copland or Prokofiev. Still, they are too rarely heard.

The Fifth comes without any program, but no music has ever offered such a gripping, dramatic scenario; the first movement sets up a chilling confrontation between humanity and soulless militarization, and the second unleashes the life force that drives everything. Storgårds felt the music down to his corpuscles and exhorted the players with everything he had. Their struggles with some of the more brutal passages (particularly the strings in the second movement) were a palpable part of the experience, but the frisson was there even if all the notes weren’t.

Storgårds had trouble separating the strands in the first movement’s climactic “fight scene” — letting the brass and percussion (which are opponents of each other) drown out the strings and woodwinds far too early. But kudos to clarinetist Loren Kitt, who handled the virtuoso part with apparent ease.

(The program will be repeated Friday and Saturday nights.)

Robert Battey is a freelance writer.