At first blush, perhaps even at second blush, the combination of string quartet and percussion ensemble seems an unlikely one. And so it is, but as the appearance of the Calder Quartet and the S? Percussion ensemble at Kutztown University Thursday night demonstrated, not an impossibility.

Of course, there's little or nothing in the traditional classical music literature for this combination, and as a result the Calder/S? combination relied on recent music of the 20th century, including two new pieces being given their world premieres.

The program began with the four members of S? performing Steve Reich's 2009 composition "Mallet Quartet," which includes two vibraphones, and two five octave marimbas, giving the composer a very wide range of notes. The three-movement work by Reich, one of the best-known of contemporary American composers, was perhaps the most traditional composition on the program, with contrasting movement structure, yet like much contemporary music, focused on rhythm and texture at least as much as development.

Daniel Wohl's Slow Wave, also for percussion, followed, with an almost complete focus on texture and sound. It also included what might be called the ninth player of the evening, electronics. In addition to the four players hitting and banging a wide variety of objects, the work also used an electronic line of the distorted sound of several percussion instruments.

Tristan Perich's Sequence for string quartet and percussion quartet with gated amplification was the next work. What the latter phrase means is that while the players bowed slow notes (all of them - even the percussionists bowed instruments that can be made to sound that way), the composer amplified the sounds and turned them on and off abruptly (the "gated" part) to create an overlaying rhythmic structure. Although I found this on the whole the least interesting piece of the evening - some of the rather pure electronic pitches reminded me of a hearing test - towards the end it began to create intriguing mental images.

The quartet had its moment to itself in Fred Frith's Lelekovice. The name of the piece is a small town in the Czech Republic which the composer had visited and which he tried to recreate musically in nine short movements of varying character, some peasanty folk, some mystical. It was effective writing for string quartet.

The evening concluded with a work for the entire group by Jason Treuting, a member of S?. Titled "Oblique Music for Four plus Four strings," it made a very good case for the evening's combination. To match the percussion, the strings were amplified, something which normally bothers me but here was essential for the balance of the piece. Using multiple pairings of groups and instruments, and a steadily rising rhythmic intensity, it was a lively and compelling work.

A major problem for a listener at a concert like this is that traditional modes of listening--following melody and harmonic progression--do not work terribly well, or even at all. Just like going to the desert and complaining about the lack of vegetation, or visiting the California redwoods and being disappointed that the trees block the view, miss the point, so does coming to a program like this and listening with traditional ears. The trick is to find the music's expectations, and that's a rewarding experience in itself.