This portfolio attempts to reach into overlooked corners of organology, examining the celesta’s aesthetic history and the more experimental practice of playing balloons. Both instruments have unusual sound qualities, which have relegated their typical musical usage to effects or gimmicks. Thus, even though they are both ubiquitous in some way— within orchestral repertoire and in daily life, respectively—the celesta and the balloon have not received significant scholarly attention thus far. “Between Worlds” explores the celesta’s historical origins, physical mechanism, and musical idioms. Behind its beloved, sparkling sound, the instrument contains many complexities. Mechanically, it combines features of keyboard and percussion, occupying a no-man’s land in terms of classification and performance technique. The sonic identity and poetic implications of the celesta are inspired by a nineteenth century marvel, the music box. As a result, its sound has taken on cultural associations, becoming a signifier for the magical, supernatural, and uncanny. Discussion of several works spanning from the eighteenth to twenty-first century demonstrate the varied ways in which composers interact with the instrument’s rich tradition. “Acts of Envelopment” is a discussion of Judy Dunaway’s work for latex balloons as a comprehensively tactile approach to music-making. She has transformed the balloon into flexible and sonically diverse instrument, developing a range of performance techniques as well as specialized notation methods. Her pieces— whether they are solo improvisations, Fluxus-style events, or sound installations— are informed by the physical properties of sound and the resulting bodily sensations that it creates. For Dunaway, each performance is an act of envelopment, both physically and metaphorically. Turning away from the object’s traditional associations with parties and humor, Dunaway’s balloon practice is also a powerful political statement that expresses her feminist views. Her singular focus on this instrument is a unique contribution to American experimentalism.