This paper examines the Middle Eastern lute, al‑ʿūd (also spelled oud), not solely as a performance instrument, but also as a theoretical instrument through which the organization of sound, scale, and proportion was conceptualized and demonstrated within medieval Islamic intellectual traditions. Central to the writings of al‑Kindi (805–873 CE), al‑Fārābī (872–950 CE), and Ṣafī al‑Dīn al‑Urmawī (1216–1294 CE), al‑ʿūd provided an acoustical and material framework that mediated between Hellenistic theoretical models and the evolving modal systems of the Islamic world, including maqām in West Asia and ṭubūʿ in North Africa, both of which remain in use today. With its four‑ to five‑course configuration, al‑ʿūd served as a tactile model for the demonstration of intervals and ratios comparable to the monochord, while simultaneously facilitating new theoretical insights into scale construction and intonation. Following Alexander Rehding’s (2016) definition, these characteristics exemplify its “music‑theoretical” function. Moreover, as outlined in the second part of al‑Fārābī’s Great Book of Music, al‑ʿūd served as a compositional and pedagogical medium linking theoretical constructs to practical application.

The westward transmission of these concepts is evident in the figure of Ziryāb, the ninth‑century Baghdadi musician whose relocation to al‑Andalus (modern‑day Andalusia, Spain) catalyzed significant developments in both musical repertoire and instrument design. The morphology of the term “lute”, derived from the Arabic word al‑ʿūd, reflects this lineage and has become the prominent label to describe a category of chordophones, including the guitar, in the Hornbostel-Sachs organology classification system (Sachs and Hornbostel 1914). Within Arabic theoretical discourse, al‑ʿūd became a reference point for explaining the maqām system, where a constituent jins (genus), tri-, tetra-, or pentachord, embodied mathematical and affective relationships between tones. These frameworks departed from ancient Greek models through the incorporation of microtonal gradations and complex modal interrelations (muttaṣil, munfaṣil, mutadākhil). Similarly, North African modal and rhythmic theories (e.g., nūbāt, ṭubūʿ) demonstrate the instrument’s continued theoretical and practical significance. By tracing these intellectual and performative continuities, this paper situates al‑ʿūd as a material, epistemic, and geographical nexus between Eastern and Western traditions of music theory from late antiquity through the modern era.

Nineteenth-century Bengal saw the emergence of a distinct music-theoretical tradition in which the sitar was not merely a performance instrument but a material agent in the production of theory. This paper argues that the period's musicology, centered on scholar-musicians like Kshetramohan Goswami (1813–1893) and Sourindro Mohun Tagore (1840–1914), constitutes a regional school shaped by an instrument-focused epistemology. In this archive, the sitar’s material configuration and teaching routines actively generate theoretical claims, most visibly in Goswami’s “dandamatrik” notation system in Sangit Sar (1869).

Building on Alexander Rehding’s concept of instruments as “epistemic things”, i.e., material objects that become sites of knowledge production, I examine how the sitar becomes epistemically productive within pedagogy, diagrammatic description, and print-based theorization. I further extend this framework by distinguishing “epistemic thing” from “co-theorist”, where, while the former describes the sitar’s role within knowledge production, the latter makes a stronger claim that the instrument’s affordances become argumentative premises shaping what counts as a concept or notational unit.

Through close reading of Sangit Sar, I demonstrate how a pedagogical teen-tar (three-string) model and the instrument’s multi-octave range inform his three-line notation system. This system does not simply translate performance into writing but reorganizes musical parameters, such as rendering pitch relations through a string-inflected visual logic while also separately regulating rhythm. Examining Tagore’s Yantra Kosha (1875) and his advocacy of “Hindu notation” reveals how sitar organology became a form of cultural argument, positioning vernacular music theory in Bangla as a sovereign and modern relative to colonial paradigms.

Finally, I place this archive within a longer genealogy of chordophones as theory-making devices. Reading Goswami and Tagore alongside the Natyasastra’s “two vīṇās” demonstration and the monochord’s role in European music theory, I argue that the sitar participates in a global lineage of material music theory. The intervention further extends Rehding’s model by foregrounding how a complex performance instrument in South Asia becomes an epistemic apparatus for theorizing music.

This paper seeks to position the baroque guitar in colonial Mexico not merely as an early modern instrument in which repertory was performed, but as a material agent—or, to use Rehding’s work, an “epistemic thing”—in which harmonic knowledge was generated, embodied, and circulated across New Spain.

Unlike the cathedral-centered polyphonic traditions preserved in staff notation, the five-course baroque guitar operated through alfabeto chord symbols and rasgueado practices, among other systems of music inscription. These notational systems encoded harmonic schemata rather than contrapuntal detail, foregrounding chordal thinking as a primary musical grammar. Manuscript sources such as the Códice Saldívar No. 4, with its use of tablature and chord letters, functioned as portable theoretical tools, allowing musicians to internalize tonal relations kinesthetically through hand shapes and strumming patterns. Taking this further, José Antonio Vargas y Guzmán’s 1776 Explicación para tocar la guitarra (Explanation for playing the guitar)—a colonial treatise produced in Veracruz—offers one of the few locally authored guides to baroque guitar technique, one in which both musica practica and theorica are front and center. In addition to providing the would-be player with guidance on rasgueado, basso continuo, and other performance practices of its day, Explicación employs the guitar, borrowing from Rehding, as an instrument of music theory: turning the guitar into a technology that theorizes harmony in the New World.

This paper also seeks to look beyond the baroque guitar not as a passive instrument, but as a site where we can understand transnational and colonial circulation, genres, race, and empire. The guitar’s material affordances (i.e., re-entrant tuning, chordal accompaniment, portability, etc.) fostered a practical harmonic consciousness that paralleled, and at times, diverged from, Iberian theoretical discourse. These affordances allowed the guitar to circulate across domestic, theatrical, devotional, and vernacular spaces, occupying a liminal status between elite and popular practices and communities. By centering the baroque guitar as an instrument of music theory, this study reframes colonial Mexican musical life not as peripheral to European theory, but as a site where theoretical knowledge was materially and racially produced, embodied, and transformed.