Numerous times during their Sprague Hall concert Tuesday evening, the venerable Czech Nonet attained chamber music nirvana. Instruments combined seamlessly, becoming a single voice that articulated melodies, colors and rhythms precisely and effortlessly. These nine musicians play together so skillfully, in fact, that it was all the more frustrating that their concert was, well, fairly dull.

Part of the problem may have been the program, which was safe and uninspiring. We’ve all had a surfeit of Mozart this season (thanks to self-satisfied celebrations of the composer’s 250th birthday), and sitting through the composer’s Concertante K. 452, an arrangement of the better-known Quintet for Piano and Winds, was more of a chore than a treat. Martinu’s Nonet no. 2, an attractive if somewhat facile neoclassical romp written for the Czech Nonet in 1959, served as the obligatory “modern” work (note to the Czech Nonet: 1959 does not count as modern anymore). A slimmed-down and rather lackluster version of Brahms’s Serenade no. 1 concluded the evening. Perhaps these conservative selections were to blame for the conspicuous lack of students in the audience (or, for that matter, of anyone under 75). The group maintains a large repertoire of Czech music that is rarely heard in this country, as well as a recently-commissioned work from American composer Robert Ward, either of which would have contributed to a more interesting program. Sadly, the Czech Nonet elected not to bring them on tour.

Even the performers sometimes seemed less than absorbed, as though playing by rote. There were bright spots, of course: Vladimíra Klanska, the group’s horn player and senior member, played with incredible control and a welcome hint of vibrato (which hornists never use here in the U.S.). Radovan Hec, the bassist, traversed his famously-awkward instrument with suave assuredness. There were times, however, when the Nonet was almost too clean; the wind section blended with each other beautifully, but they also failed to bring any raucous interplay to the Martinu. Violinist Ludek Ruzicka consistently disappointed; his solos in the Mozart seemed blustery and under-rehearsed, and there was no warmth in his soaring lines in the Brahms. The group plays without a conductor and takes great pains to hide the mechanisms used to communicate with each other, but I missed the physicality evident in truly dedicated chamber performances.

Performing music is an inexact science, of course, and many elements contribute to engaging an audience. It’s possible that the Nonet was just having an off night as they near the end of their U.S. tour. But that’s no excuse; the group is so technically proficient and has such promise that their failure to excite was all the more disappointing.