This article describes a set of “textual” technological practices that have been emerging over the past decade in the work of underground electroacoustic and computer music composers, focusing particularly on Florian Hecker and Russell Haswell. Guided by methodological insights from the field of software studies, the article zooms in on two computer programs, PulsarGenerator and GENDYN, presenting a genealogical analysis of them as cultural objects and outlining how these lines of descent are aestheticized in their works. In the hands of these artists, sound synthesis procedures carry an author function, and this transgresses both their legal status as technological “inventions” rather than texts, as well as their ontological status in the electroacoustic music genre. Combined with a compositional focus on “sounding” the materiality of these technologies—the particular affordances, limitations, and quirks of their operative functioning—this textual practice contributes to a new aesthetic, one that challenges the prevailing logic of secrecy, alchemy, and semblance in this music. Using the notion of “ontological politics” inherited from science and technology studies, I show how these practices highlight zones of contestation over electroacoustic music’s ontology.