As a graduate student, Leslie Tilley spent years studying and practicing the music of Bali, Indonesia, including a traditional technique in which two Balinese drummers play intricately interlocking rhythms while simultaneously improvising. It was beautiful and compelling music, which Tilley heard an unexpected insight about one day.
"The higher drum is the bus driver, and the lower drum is the person who puts the bags on the top of the bus," a Balinese musician told Tilley.
Today, Tilley is an MIT faculty member who works as both an ethnomusicologist, studying music in its cultural settings, and a music theorist, analyzing its formal principles. The tools of music theory have long been applied to, say, Bach, and rather less often to Balinese drumming. But one of Tilley's interests is building music theory across boundaries. As she recognized, the drummer's bus driver analogy is a piece of theory.
"That doesn't feel like the music theory I had learned, but that is 100 percent music theory," Tilley said. "What is the relationship between the drummers? The higher drum has to stick to a smaller subset of rhythms so that the lower drum has more freedom to improvise around. Putting it that way is just a different music-theoretical language."
Tilley's anecdote touches on many aspects of her career: Her work ranges widely, while linking theory, practice, and learning. Her studies in Bali became the basis for an award-winning book, which uses Balinese music as a case study for a more generalized framework about collective improvisation, one that can apply to any type of music.
Currently, Tilley is engaged in another major project, supported by a multiyear, $500,000 Mellon Foundation grant, to develop a reimagined music theory curriculum. That project aims to produce an alternative four-semester open access music theory curriculum with a broader scope than many existing course materials, to be accompanied by a new audio-visual textbook. The effort includes a major conference later this year that Tilley is organizing, and is designed as a collaborative project; she will work with other scholars on the curriculum and textbook, with 2028 as a completion date.
If that weren't enough, Tilley is also working on a new book about the phenomenon of cover songs in modern pop music, from the 1950s onward. Here too, Tilley is combining careful cultural analysis of select popular artists and their work, along with a formal examination of the musical choices they have made while developing cover versions of songs.
All told, understanding how music works within a culture, while understanding the inner workings of music, can deliver us new insights - about music, performers, and audiences.
"What I am focused on fundamentally is how musicians take a musical thing and make something new out of it," Tilley says. "And then how listeners react to that thing. What is happening here musically? And can that explain the human reaction to it, which is messy and subjective?"
Across all these projects, Tilley has been a consistently innovative scholar who reshapes existing genres of work. For her research and teaching, Tilley has received tenure and is now an associate professor in MIT's Music and Theater Arts Program.
The joy of collective improv
Both of Tilley's parents were musicians, but "they never had any intention for their kids to go into music," says Tilley, a native of Halifax, Nova Scotia. Growing up, she studied piano, violin, and French horn for years; played in a symphony orchestra, brass band, and concert bands; sang in choirs; and performed in musicals. Ultimately she realized she could make a career out of music as well.
"In 12th grade I suddenly realized, music is what I do. Music is who I am. Music is what I love," Tilley says. Back then, she pictured herself being an opera singer. Subsequently, as she recalls, "Somewhere along the way, I steered myself into music scholarship."
Tilley received her bachelor of music degree from Acadia University in Nova Scotia, and then conducted her graduate studies in music at the University of British Columbia, where she earned an MA and PhD. It was in graduate school that Tilley began studying the music of Bali - on campus and during extended periods of field research.
Studying Balinese music was "mildly accidental," Tilley says, calling it "a little bit of happy happenstance. Encountering these musical traditions exploded the way I thought about music and ways of understanding the interactions of musicians."
In her research, Tilley looked intensively at two distinct improvised Balinese musical practices: the four-person melodic gong technique "reyong norot" and the two-person drumming practice "kendang arja." Both are featured in her 2019 book, "Making It Up Together: The Art of Collective Improvisation in Balinese Music and Beyond." Published by the University of Chicago Press, it won the 2022 Emerging Scholar Award from the Society for Music Theory.
Grounded in empirical evidence, the book proposes a novel, universal framework for understanding the components of collective improvisation. That includes both the more strictly musical aspects of improvisation - how much flexibility musicians give themselves to improvise, for instance - as well as the forms of interaction musicians have with their co-performers.
"My book is about collective improvisation and what it means," Tilley says. "What is the give and take of that process, and how can we analyze that? There are lots of scholars who have discussed collective improvisation as it exists in jazz. The delicious joy of collective improvisation is something anybody who improvises in a musical group will talk about. My book looks at examples, especially the case studies I have from Bali, and then creates bigger analytical frameworks, so there can finally be an umbrella way of looking at this phenomenon across music cultures and practices."
Despite her years of immersing herself in the music, and playing it, Tilley says, "I am a beginner in comparison to the drummers I studied with, who have been playing forever and played with other masters their whole lives, and were generous enough to allow me to learn from them." Still, she thinks the experience of playing music while studying it is indispensable.
"Ethnomusicology is a field that takes a bit from other fields," Tilley notes. "The idea of participant observation, we borrow that from anthropology, and the idea of close musical analysis is from musicology or music theory. It's an in-between way of thinking about music where I get to both participate and observe. But also I'm a music analysis nerd: What's happening in the notes? Looking at music note-by-note, but from a place of physical embodiment, provides a better understanding than if I had just looked at the notes."
Expanding instruction
At present, Tilley is devoting significant effort to her music-theory curriculum work, which is funded by the Mellon Foundation as a three-year effort. The upcoming summer conference she is organizing, also supported by the Mellon Foundation, will be a key part of the project, allowing a wide range of scholars to air perspectives about reimagining music theory studies in the 21st century.
Substantively, the idea is to broaden the scope of music theory instruction. Often, Tilley says, "music theory is learning how to understand the musical structures that are essentially between Bach and early Beethoven, that kind of narrow range of a couple hundred years, really amazing musical systems with a very deep, written-down music theory. But that accepted canon leaves out so many other kinds of music and ways of knowing." Instead, she adds, "If we were not beholden to any assumptions about what we should have in a music program, what skills would we want our students to walk away from four semesters of music theory with?"
About the conference, Tilley quips: "Sitting in a room and nerding out with a bunch of people who care deeply about a thing you care about, which in my case is music, music theory, and pedagogy, is possibly the coolest thing you can do with your time. Hopefully something wonderful comes out of it."
As Tilley views it, her current book project on pop music cover songs stems from some of the same issues that have long animated her thinking: How do artists fashion their work out of existing knowledge?
"The project on cover songs is similar to the project on collective improvisation in Bali," Tilley says, in the sense that when it comes to improvisation, "I have a bank of things I know, in my head and in my body about this musical practice, and within that context I can create something that is new and mine, based on something that exists already."
She adds: "Cover songs to me are the same, but different. The same in that it's a musical transformation, but different because a pop song doesn't just have lyrics, melody, and chords, but the vocal quality, the arrangement, the brand of the performer, and so much more. What we think about in popular music isn't just the song, it's the person singing it, the social and political contexts, and the listener's personal relationships to all those things, and they're so wrapped up together we almost can't disentangle them."
As with her earlier work, Tilley is not just examining individual pieces of music, but building a larger analytical model in the process - one that factors in the formal musical changes artists make as well as the cultural components of the phenomenon, to understand why cover songs can produce strong and varying reactions among listeners.
In the process, Tilley has been presenting conference papers and invited talks on the topic for a number of years now. One case that interests Tilley is the singer-songwriter Tori Amos, whose many cover versions transform the viewpoint, music, and meaning of songs by artists from Eminem to Nirvana, and more. There may also be some Taylor Swift content in the next book, although with thousands and thousands of songs to choose from in the pop-rock era, there could be something for everyone - fitting Tilley's ethos of studying music broadly, across time and space as it is created, recreated, and recreated again.
"This is why music is infinitely cool," Tilley says. "It's so malleable, and so open to interpretation."
