Tilley received a BMus from Acadia University and her MA and PhD from the University of British Columbia. Her book, Making It Up Together: The Art of Collective Improvisation in Balinese Music and Beyond, was published by the University of Chicago Press in 2019. It is a sweeping study of collectively improvised practice, which proposes new, cross-culturally applicable models for the analysis of both improvisatory process and collective creation, demonstrating their analytic power through the close musical examination of two collectively improvised practices from Bali, Indonesia: the four-person melodic reyong norot practice and the paired interlocking drumming tradition kendang arja. The book won the prestigious Emerging Scholar Award from the Society for Music Theory (SMT) in 2022.
Tilley’s work at once delves deeply into musical particulars and proposes broad-reaching analytical approaches and disciplinary interventions. In various articles and chapters in edited volumes, she has explored ways that ethnography and fieldwork methods can nuance the music analysis of kendang arja improvisation; borrowed theories of linguistic diffusion and variation to explain how improvised arja drum patterns move and change across time and space; analyzed influences of Balinese music on 20th-century Western composers; proposed new pedagogical models for teaching gamelan outside Indonesia; broadly examined and critiqued the many analytical methods used by ethnomusicologists over the last 140 years and, in a collaboratively-written piece, examined the challenges, goals, disagreements, and possible ways forward for diversifying and decolonizing music theory pedagogy.
Tilley’s newest work moves in two directions simultaneously. The first expands the purview of her forays into musical transformation, seeking ways to analyze the complex creativity-within-constraint inherent in the creation and reception of popular music cover songs. She has presented this work at several national and international conferences including, among others, Analytical Approaches to World Music (AAWM), Society for Ethnomusicology (SEM), Society for Music Theory (SMT), International Association for the Study of Popular Music (IASPM), and Society for Music Analysis (SMA). She has also written a chapter in the volume The Routledge Handbook to the Popular Music Cover Song: Vivid Versions and Musical Subjectivities. Tilley’s second research agenda delves more deeply into pedagogical innovation and equity, particularly in the field of music theory. She was a guest editor for the journal issue Engaging Students: Essays in Music Pedagogy 8: “Beyond Western Musicalities,” which won the SMT Outstanding Multiauthor Publication Award in 2023. She was a keynote speaker at the 2025 Practitioner-Centered Music Theory conference. And in December 2024, she was awarded a 3-year Higher Learning research grant from the Andrew W. Mellon Foundation to co-create a new alternative open access undergraduate music theory curriculum.
Tilley regularly teaches 21M.052: Rhythms of the World, an innovative cross-cultural music fundamentals course of her own design, as well as 21M.292: Musics in Bali and 21M.051: Fundamentals of (Tonal) Music. She has also taught an Advanced Seminar in Music (21M.500) on Analyzing Popular Music, the research methods class Thinking Critically in Music (21M.540/21M.240), and Introduction to Musics of the World (21M.030), and she has led the MIT Balinese Gamelan (21M.450).