On his recent electroacoustic CD Espaces tautologiques, composer James O’Callaghan takes us down the rabbit hole into a visceral, endogenous acousmatic wonderland. Although tautologies can be defined as “needless” repetitions, for O’Callaghan, they instead may be an ironic unifying premise for his vagabond auditory adventures, or append extra significance to compositional procedures such as varied repetition, imitation, and augmentation. The first three pieces (Objects-Interiors, Bodies-Soundings, and Empties-Impetus) form a triptych that “imagine(s) the sounding bodies of instruments as resonant spaces.” They contain crisp, natural, and remodelled recordings of passages through remote instrumental spaces, and at times it feels as though the listener is situated inside the instrument. From the rim to the spine of a piano (Objects-Interiors), an acoustic guitar and toy piano (Bodies-Soundings), or the surfaces and recesses of instruments in a string quartet (Empties-Impetus), each piece celebrates the percussions and resonances of a similar, colourful palette of instrumental and digital treatments. O’Callaghan demonstrates fluency with standard techniques of electroacoustic music, but it’s the impetus of the philosophical aspects that takes the pieces to their most compelling territories. The last piece, Isomorphic, is a particularly captivating jaunt through protractions of carefully ordered squealing, chattering textures. While the work shifts from one archetype to another, it’s coherently driven by consecutive, playful morphological relationships that extend from one sound to the next, despite differences of sound source and context. By virtue of the gesture, contour, pitch, and timbral coherence of his materials, O’Callaghan proposes contrasting ways to consider the ornithological chirps, industrial doors, and ambient environments. They can be heard as a perpetual flow, in which all sounds are related as one, or as a duality in which the listener simultaneously compares the ongoing profile similarities of the sounds with their wildly differing origins.