Music is mystifying in all of its simplicities, representative of one of the sensory experiences that can be understood scientifically, so it begs the question of why music compels us emotionally and spiritually. Simply, it is made of rhythms, organized vibrations moving through the air, but mystifying in the way that while we cannot physically see it, we can feel it. Music can bring forth feelings of nostalgia, tension, peace, grief, longing or joy. Even without words, music can invoke intense physical reactions, sometimes associated with healing and growth, but is there hard evidence to support the healing power of music?
Music exists between mathematics and emotions. It can scientifically be explained as structured and measurable, but also deeply personal and subjective. The same sequence of sounds can mean entirely different things to people depending on their culture, individual memory, and experiences.
Researchers can explain how certain intervals create tension or why rhythm affects the nervous system. This article is an examination of “The Perception of Tension in Harmonic Intervals Across Indian and Western Listeners: The Roles of Psychoacoustics and Musical Expertise” by Imre Lahdelma et al. in 2025. The study asks, “Are the reactions which people have to music universal because of physics and the ear? Or do culture and musical experience shape them?”
What makes a good sound versus what is a bad sound? When two notes are played together, it can be a combination that sounds stable and calm, or chaotic and harsh. These two combinations are key terms in music theory, known as consonance and dissonance. Consonance is smooth, resolved and stable, while dissonance is rough and tense. Roughness is another key term that describes how, when two frequencies are close together, the sound waves interfere and create a “beating” or rough sensation.
Different intervals play key roles in our mathematical understanding of music. For example, the concept of perfect fifths, which are highly harmonic and known to sound smooth, with a very stable octave, a minor second, which is tense/dissonant, known to sound rough, and a major seventh, which is tense and less harmonic. We perceive these sounds from smooth to rough because of the way that our brains process the sound waves. Our brains perceive sounds that create wave patterns that are more evenly aligned as smooth, while complex ratio intervals clash and are known as “beating.”
The study tested 133 people, separating them into four groups: Indian musicians, Indian non-musicians, Western musicians and Western non-musicians. They played all 12 intervals of music and asked each participant to rate each interval on a scale of 1-7.
They discovered that Western musicians followed the “expected” acoustic rules most strongly. For Western musicians, rough intervals sounded tense, while harmonic intervals sounded relaxed. Indian musicians were surprisingly similar to Western musicians, while the Indian non-musicians did NOT strongly associate roughness with tension, often rating dissonant intervals as less tense than Western listeners did. This challenges the perception that music is universal.
This also sheds light on how our taste in sound is shaped by the world around us. Many Indian listeners grew up on Hindustani classical music or Carnatic music, which trained the brain to have different emotional rules than Westerners. Our minds become accustomed to predicting patterns in the music we are around. While we do not all love the same sounds universally, all around the world, people prove that they love sound.
