Hamburg-based trumpeter Birgit Ulher uses her improvisational prowess to shape this program, treating as full partners the extended drones and blurry hisses that emanate from a stand-alone radio and its speaker. On the nine mid-length tracks here—all with the suffixes ‑welle or ‑wave—buzzing mouthpiece growls, and prolonged, strident whines enliven, wrap up, or complement the unpremeditated waveforms and sideband echoes heard from the untouched radio.
 
Propelling air through her horn without valve movement, humming nonsense syllables along with discordant tones or gutturally popping split tones, Ulher amplifies her oral attacks with lip bubbling, shrill whistles, and chromatic tongue slaps, often reaching sonic union with the barely audible static interference. Although carefully inserted bell-mutes impede full-force blowing, she prominently exposes understated droning burrs, altissimo whistling cries, or pedal-point forced guttural tones, on tracks such as Langwelle. Or she uses gargles and reflux as a unique performance strategy, as on Dezimeterwelle.
 
Cunningly divorcing her horn sounds from their characteristic showy brassiness, Ulher patches trumpet textures into the mix, matching the other waveforms. By refusing to acknowledge a brass instrument’s stock sound, and by not acquiescing to serendipitously created sonic oscillations, she has produced an original and memorable CD.