In catena, the typical tone production of the piano is altered to include spectral microtonality and inharmonic timbres. Pitches were derived from the superimposition of harmonic spectra drawn from two fundamental pitches. Additionally, the spectra of single notes are often rendered inharmonic using a digital signal process that maps the formant regions of one sound to another. While never straying far from its identity as ‘piano,’ in catena the instrument rarely behaves normally. Instead, it acts as a kind of hyper-instrument, characterized by increased pitch resolution, gestural complexity, and spectromorphological control.