“Sing the word ‘toad,’ beginning on a low pitch (for your range) and instantly sliding up in pitch in glissando (like a siren).”

This was one of the instructions given to a bewildered audience last Saturday, at the concert of the Harvard University Wind Ensemble. The program, “Music for Audience and Soloist,” by Elliott Schwartz, the featured composer of the evening, asked the audience to make different sounds, with the intended effect of organized chaos.

The small audience, obliged good naturedly, struggling, upon Schwartz’s instructions, to “blow air through mouth without pitch,” in “U.S. Indian war-whoop fashion.”

The first half of the program was sedate in comparison to the engaging second. The opening piece, “Smetana Fanfare,” by Czech composer Karl Husa, opened with majestic held chords, but then devolved into a monotone rhythm exercise, suggestive of an abridged version of “Mars,” from Gustav Holst’s “The Planets.”

The performers, despite some intonation difficulties in the upper winds, produced a powerful sound, while retaining control. They retuned before the second piece, Johann Sebastian Bach’s “Fantasia in G, BWV 572,” originally written for organ. The richness of the low brass made this atypical arrangement convincing, although anyone seeking to envision it as authentic was jarringly shaken back into the twenty-first century with the crashing cymbal at the end.

The “Concertino in Eb for Trombone and Orchestra,” by Ferdinand David, was acoustically the highlight of the evening. Professional soloist Nathaniel Dickey produced a tone sweet and pure, impressing the audience with his own virtuosic skills on the trombone and conveying a sensitivity the instrument is not usually associated with.

The last piece before the intermission, Robert Russell Bennet’s “Suite of Old American Dances,” was charming but too slow, making this “bright-eyed tune” somewhat lackluster.

In the second half of the program, the composer, Mr. Schwartz divided the audience into four groups, explaining that his piece, “Music for Audience and Soloist” originated as an activity at a conference for gifted teenagers in Maine.

Each group was assigned a conductor (a student member of the wind ensemble) and given a list of noises to be produced, as directed by the conductor. Among the requests to snap, stomp, and cluck, was one particularly challenging assignment: “With mouth closed, project the highest and loudest sound you can, very sharply. This should sound like the squeak of a gigantic mouse.”

The barnyard audience served as accompaniment to a solo improvising clarinetist, Matt Katcher ’05, who weaved in and out of the busy audience, and whose improvisation at times sounded remarkably like Mozart’s clarinet concerto. When Katcher stopped playing and shouted “never!” the piece had two minutes remaining.

The concept of involving the audience in a performance is certainly engaging, though the excitement of the four-year-old in the front row testified to the fact that the piece might have been better received (and performed) in an elementary school music class. The acoustic result was initially interesting, but once the novelty wore off, simply chaotic.

The last piece of the program, “Downtown Crossing,” was the world premier of Schwartz’s own composition. Paying homage to the title, Lowell Lecture Hall was decked out in balloon-lined music stands connected by colored tape covering the floor, representing the major stations and lines of the Boston T subway system.

In a lengthy introduction, Schwartz, the Beckwith Professor of Music (Emeritus) at Bowdoin College, explained his recent fascination with maps and patterns as guides for musical journeys. Although he lost much of his audience with an analysis of New York Times crossword puzzles (“This is a very Weber-esque puzzle,” he explained at one point) the samples of musical scores, resembling board games, were fascinating.

A double trombone concerto with wind ensemble accompaniment ensued, with the soloists walking along the map of the T. At every major junction, such as Park Street, the composer narrated a brief tourist-guide blurb regarding the history and interest of that point in the city, culminating in a glorious explosion of sound surrounding the arrival of the soloists at Harvard Square.

At one point the entire ensemble went silent while one of the solo trombone players screamed, then kissed his instrument. The incongruence of this act in the midst of a night of classical music tellingly revealed the peculiarity of the program.

It is clear that the Wind Ensemble worked hard to produce such a complicated show. And to be sure, whatever may have been lacking musically in the first half was more than compensated for by the excitement and diversity of the second. In the end, the evening was an irreproducible and unforgettable journey into the eccentric, occasionally war-whoop-filed world of avant-garde contemporary classical music.

—Reviewer Madeleine Bäverstam can be reached at mbaverst@fas.harvard.edu.