Imagine listening to the famous soprano Maria Callas (1923–1977) singing the aria “Vissi d’arte” from Puccini’s Tosca. How would you describe the quality of her voice? When describing the timbre of musical sounds, listeners use descriptions such as bright, heavy, round, and rough, among others. In 1890, Stumpf theorized that this diverse vocabulary can be summarized, on the basis of semantic proximities, by three pairs of opposites: dark–bright, soft–rough, and full–empty. Empirical findings across many semantic differential studies from the late 1950s until today have generally confirmed that these are the salient dimensions of timbre semantics. However, most prior work has considered only orchestral instruments, with relatively little attention given to sung tones. At the same time, research on the perception of singing voice quality has primarily focused on verbal attributes associated with phonation type, voice classification, vocal register, vowel intelligibility, and vibrato. Descriptions like pressed, soprano, falsetto, hoarse, or wobble, albeit in themselves a type of timbre semantics, are essentially sound source identifiers acting as semantic descriptors. It remains an open question as to whether the timbral attributes of sung tones, that is verbal attributes that bear no source associations, can be described adequately on the basis of the bright-rough-full semantic space. We present a meta-analysis of previous research on verbal attributes of singing voice timbre that covers not only pedagogical texts but also work from music cognition, psychoacoustics, music information retrieval, musicology, and ethnomusicology. The meta-analysis lays the groundwork for a semantic differential study of sung sounds, providing a more appropriate lexicon on which to draw than simply using verbal scales from related work on instrumental timbre. The meta-analysis will be complemented by a psycholinguistic analysis of free verbalizations provided by singing teachers in a listening test and an acoustic analysis of the tested stimuli. --