The first time I encountered a Gamelan was for an undergraduate world music course at Northwestern University in 2015. A small troupe of visiting musicians from Indonesia had set up a small Gamelan on the second floor of Alice Millar Chapel and gave an introductory lesson to our class of twenty, maybe twenty-five music students. The students giggled and gawked at this ensemble that was so simple in its mechanics (hold hammer, hit key; hold mallet, hit gong) yet so unfamiliar in its sound: the ringing, shimmering sound of bronze and the pure yet strange overtones of resonating metal clashing with the other instruments. The out of tune-ness of the Gamelan.

My second encounter of the Gamelan was as a GSI for Musicology 139, Introduction to the Study of Musicology. Each semester, Professor Susan Walton and the standing Gamelan GSI brought a cartful of instruments to the stage of Britton Recital Hall. The half-hour lesson calls small groups of students to the stage to play the instruments while Professor Walton divides the hall in three parts to teach the class the underlying beat structure of Gamelan to the class.

And then we talk about tuning. Gamelan has two tuning systems: sléndro and pelog. Sléndro is composed of a five-note scale with each pitch roughly equidistant from the next, while pélog is a seven-note scale from which five-note modes are constructed. Students are shown some variation on the concept of Wasisto Surjodiningrat’s 1972 transcription of Gamelan Mardiswara and how it compares to the Western major scale.

The discussion of tuning in the gamelan dovetails nicely into the early roots of ethnomusicology, particularly of Alexander Ellis devising the system of dividing a Western octave into 1200 cents (100 cents between each of the 12 semitones), and of German ethnomusicologist Jaap Kunst traveling throughout Indonesia and measuring the keys pitches of each Gamelan set to the Hertz. These exercises in mathematical measurement all characterize the nature of the Western encounter with the Gamelan: it sounds out of tune, but why? What is the math behind this? What is the science behind this?

Subsequent ethnomusicologists – like Carterette and Kendall’s 1994 article “On the Tuning and Stretched Octave of Javanese Gamelans – have attempted to derive elaborate mathematical equations from the pitches of Gamelan sets to explain this out of tune-ness, but they miss a very simple point: their notion of tuning as a scientific system of measurement based on the purity of the octave does not exist in Javanese Gamelan.

In Gamelan sets, the octave is not based on the mathematical doubling and halving of pitch frequencies. Each Gamelan has a unique spirit poured and hammered from molten bronze, housed across the full body of its instruments. The pitches of the Gamelan are anchored to the gong and overseen by the intuition of a pasindhen, or female singer, and the octave in each Gamelan is slightly larger or smaller than its Western counterpart. This ensures that the instruments in each register create a shimmering effect when played together, in comparison to the Western notion of pure resonance and tuning. Crucially, to copy the pitches of a Gamelan is to insult the spirit housed within it.

In short, the out of tune-ness of Javanese Gamelan is relative to Western standards of tuning and scientifically dividing pitches. To perceive a Gamelan as out of tune is to miss the point that the spirit of the Gamelan is unique to each set in a way that resists tuning. Hearing a Gamelan as “in tune” thus requires sitting with the instruments – playing them, listening to the pitches, and singing them back: imbibing the spirit of the ensemble.