Princeton University is steeped in tradition, as is classical music, but music is a continually evolving medium. Well into the second decade of the 21st century, the University’s department of music has established a new residency collaboration with one of music’s most innovative ensembles. So^– Percussion, a quartet of four human rhythm machines who have been performing together for 15 years, opened its residency with a concert in Richardson Auditorium last Friday night. Following the former Edward T. Cone Performers-in-Residence — the mufti-faceted Brentano String Quartet, So^– Percussion may have had a big job introducing their repertoire and style of music to the Princeton audience. However the four musicians of So^– Percussion (Eric Beach, Josh Quillen, Adam Sliwinski, and Jason Treuting) are no strangers to the Princeton community and quickly made themselves at home.

The New York Times recently called the percussion ensemble the “string quartet of the 21st century,” and attendees at orchestra concerts can easily make an evening out of watching the percussion section. It is therefore no surprise that the percussion section has stepped out of the orchestra on its own as a performing ensemble. Melodic line and sinuous melodies may not always be present in the repertoire of percussion ensembles, but Friday night’s concert showed that great variety could be found in the diversity of instruments and rhythmic intensity of the music.

So^– Percussion presented three works from the 20th and 21st century, one of which demonstrated that music for this genre goes back further than one would think. American composer John Cage composed Third Construction in 1941, surely before anyone thought this medium would be popular. Cage wrote this one movement work for both traditional instruments and objects found around the house. So^– Percussion set the stage with a collection of drums, as well as tin cans, South American and Northwest Indian instruments, and some of the lesser-heard instruments of the orchestra. Composed for a very early percussion ensemble with which Cage was involved in the 1940s, Third Construction required each musician of So^– Percussion to play at least five instruments. All players demonstrated exacting rhythm and communication with one another. Among the more unique instruments played were Northwest Indian rattles, claves, a conch, and a “lion’s roar” — a membranophone bringing of a sound from the depths.

As an ensemble, So^– Percussion not only focuses on music of the past century, but also creates its own repertory. In 2006 founding member Jason Treuting created a series of short pieces entitled amid the noise, several of which were performed in this concert. Again, each musician played multiple instruments at once, and especially in the first “life is (blank)” the rhythm and percussive action were so fast it was difficult to tell who was playing what instrument when. The second and more improvisatory “June” contrasted pitched percussion instruments with an electronic drone carried through the audience and to various parts of the stage. The “noises” of amid the noise are sounds of both traditional classical music and sounds of the concert hall in which the piece is played. Audience involvement is another component of So^– Percussion performances, and the audience at Richardson was more than willing to participate.

So^– Percussion likes to devote the second half of the ensemble’s concerts to a single work, and Bryce Dessner’s 2013 Music for Wood and Strings showed innovation both in compositional style and instrumentation. Dessner composed this work for four “chordsticks,” a newly-invented instrument which was a cross between a guitar and hammered dulcimer. Resembling a zither and played with sticks the size of pencils, the “chordstick” was fretted as a guitar, yet also bowed with a violin bow at times. The four members of So^– Percussion each played one of these instruments throughout Dessner’s piece, creating a more mellow sound than one would hear from a dulcimer. The music appeared to be notated on cards (with Mr. Sliwinski impressively playing without any apparent written score) and the overall effect built in intensity as the piece went on.

Music in the 21st century has entered a new era of evolution, and Princeton University has placed itself in the thick of it with the appointment of So^– Percussion as performers-in-residence. Much of the ensemble’s responsibilities will involve working with students, which will no doubt open up new avenues of creativity within the department of music. Princeton audiences as well will surely enjoy hearing music at its evolutionary best through this unique ensemble.