Newswise — If you’ve ever caught a concert of experimental music, or watched a parent's bewildered reactions to their teenager's current playlist, perhaps you’ve witnessed it: some listeners are emotionally transported by a pleasing musical experience, while others wince at what they hear as only noise.

How can people interpret the same sounds so differently? One answer is timbre, according to Zachary Wallmark, an assistant professor of musicology at the University of Oregon.

Timbre — that’s pronounced “TAM-ber” not “TIM-ber” — is the quality of sound that makes each instrument and voice unique. Wallmark, of the School of Music and Dance, explores timbre and what draws listeners to a particular sound.

“People have been grappling with the mysteries of music since antiquity,” Wallmark said. “Of course, there are the unique notes, rhythms and lyrics that make up your favorite songs. But there’s also something about musical experience that’s hard to describe but absolutely essential: timbre.”

Wallmark has taught undergraduate and graduate courses on American popular music history and analysis, music and emotion, film music, hip-hop, music and politics, and opera, among other topics. Working at the intersection of the cognitive sciences and musicology, he studies the role of musical timbre or tone in emotional response, aesthetic judgment and music sociology, particularly in the context of post-1945 American popular music.

In "What is Timbre? Why people interpret sounds differently," Wallmark describes three layers important in understanding how the concept works in music: physical, perceptual and social qualities of timbre.

Physical qualities refer to physical waveforms of sounds produced by different sources; a violin sounds nothing like a trumpet, for example, even when both are played in the same pitch. What is heard, Wallmark said, isn’t solely a pure note at a single frequency, but overtones at various higher frequencies unique to each instrument.

Also important to timbre is a paradox regarding perception: Not all people perceive the same sound identically. Listeners hear their own patterns in the same sound.

“Timbre is ‘perceptually malleable’ between different people,” Wallmark said.

Timbre also has social qualities. Consider the “twang” of country music. This timbre is instantly recognizable and imbued with meaning for listeners familiar with the genre, Wallmark said. For some, the twangy timbre of country music signifies something positive, a proud identification with rural life or the South, for example. For others, this same twang signifies something else entirely.

“Timbre is a crucial but elusive feature of music,” Wallmark said. “Although we might not like all the music we hear, we should have a greater appreciation for the complexity of sound and human perception.”