“Wheel: mechanical, circular motion. The brake was invented later.”

Enno Poppe’s words about Rad (“Wheel”), the first piece on his Composer Portraits concert at Miller Theatre on Saturday night, express well the experience of listening to it. With their two keyboards connected to computers that allowed them to play a huge array of scales in multiple tunings, Laura Barger and Ning Yu of Yarn/Wire gave a dizzying, athletic performance of the piece, which Barger related afterwards left her and Yu feeling almost like madwomen.

The two seemingly independent parts were in actuality completely synchronized, requiring the keyboardists to play extremely complex rhythms while staying in perfect time with each other. Though the instruments were programmed to produce sampled piano sounds, the continual changes in tuning, triggered by the keyboardists pushing a button on the side of the instrument, added a disorienting layer to the music. The sound fluctuated between acoustic piano and unrecognizable synthesized effect, completely turning the concept of pitch and timbre on its head.

With Schweiss Barger, playing a muted organ sound on the keyboard, and Kevin McFarland, performing a muted cello part, provided a nice cool-down. Working his way up from a low A to the A two octaves higher (all played on the bottom string), McFarland played short portamento gestures that sounded like a voice moaning. The piece is from a larger work, the cello part having originally been scored for a male singer playing Robinson Crusoe, in a scene in which his attempts to make his own medicine go slightly awry.

As Poppe related in his post-intermission discussion with McFarland, Tier and Rad are “unequal twins” in that both deal with movement, the former dealing with animal movement and the latter dealing with machine movement. The piece did indeed resemble its “twin”, the use of quarter-tones creating a sense of disorientation, and the JACK Quartet jumping expertly around on their instruments in a frenzy of music activity.

The evening ended with Tonband (“Audiotape”) for two percussionists and two keyboardists, co-written by Poppe and Wolfgang Heiniger (who creates the sound patches for the electronic components of Poppe’s pieces). Though the title of the piece might seem to indicate otherwise, Heiniger stated in the mid-concert discussion that it is the “total opposite of a tape piece”, as all of the sounds are created directly from the instruments. Nonetheless, Poppe related that the resulting effect often sounds like tape music, “as if we could play Stockhausen live”.

Performing on a wide variety of instruments, percussionists Ian Antonio and Russell Greenberg provided the raw material for Barger and Yu to play, the sounds from the percussion instruments going via microphone through the computers to the keyboards. Thus, while all four had their own individual musical parts, the resulting sound of the keyboards was entirely dependent on what was happening in the percussion; it was quite interesting to get the acoustic sound simultaneously with the electronic render. Stunningly virtuosic in their adept handling of the music, Yarn/Wire created an incredibly varied sound pallette, at times a veritable rainstorm of musical activity, and managed an almost overwhelmingly loud climax about two-thirds of the way in, leaving the air quivering for the piece’s denouement.

When asked by McFarland about his thoughts on experimentation, Poppe replied “I believe experimentation is very important, [but] there’s the research and then there’s the art. I want to show what is artistic and emotional... I want to show not just the technical but more than that.”