The energy of music: the physics of an emotion

From the vibration of a string to the energy that powers a concert or music festival: the physical journey that transforms sound into a collective experience.

When we talk about the «energy» of a concert, we’re describing an almost tangible emotion. And yet, it’s not just a metaphor. Music is a physical, measurable transfer of energy, a process that begins with a gesture and is completed in our perception. Analyzing its physics doesn’t take away from its magic, on the contrary, it reveals its deeper value, showing how the world of vibrations translates into the universal language of emotions.

The first impulse: vibration

Every sound we know, from the riff of an electric guitar to the softest voice, begins with a fundamental energetic act: a vibration. When a musician plucks a string, strikes a drumhead, or pushes air through vocal cords, they are transferring energy, forcing the instrument into oscillatory motion.

From a physical standpoint, this involves a continuous conversion between potential energy - accumulated when the object is at its maximum tension - and kinetic energy, released during motion. It’s the same principle that governs the swing of a pendulum. This energy transfer is the initial impulse that sets the musical process in motion. The cone of a loudspeaker, for example, moves back and forth, driven by electrical signals, simply replicating the original vibration and generating sound waves that begin their journey.

The journey of energy: the sound wave

But how does that vibration reach us? Through an extraordinary vehicle: the sound wave. Contrary to what one might think, it’s not a flow of air but a pressure wave. The vibrating object compresses nearby air molecules (compression), then moves in the opposite direction and disperses them (rarefaction). This disturbance propagates through the environment, carrying energy, not matter.

The best analogy is a stone thrown into a pond: the impact creates waves that carry energy. Similarly, sound waves make air molecules oscillate, allowing energy to travel.

The characteristics of this wave define what we perceive as music:

• Amplitude: this is the wave’s intensity, its "height." A wave with greater amplitude carries more energy, which we perceive as higher volume. It’s the physical difference between a whisper and a scream. At a concert, the energy carried by low-frequency bass waves is so intense that we don’t just hear it, we feel it vibrating in our chest.
• Frequency: the number of oscillations per second, measured in Hertz (Hz), which determines pitch. High frequencies produce high-pitched sounds; low frequencies produce deep tones.
• Timbre: the specific "shape" of the wave, allowing us to distinguish a piano from a violin even if they play the same note at the same volume. It’s the secondary waves (harmonics) that form the unmistakable “fingerprint” of a sound.

Resonance: when energy amplifies

Resonance is a key phenomenon in acoustic physics. It occurs when a sound wave causes another object to vibrate at its own natural frequency, transferring energy extremely efficiently and amplifying movement. The soundboard of an acoustic guitar, for example, is designed to resonate with the strings, amplifying a sound that would otherwise be weak. In enclosed spaces like theatres or arenas, resonance contributes to a sense of immersion, where sound is not only heard but physically felt.

The destination: from ear to brain

The journey of the sound wave ends in our ear, a sophisticated biological transducer. The mechanical energy of the wave vibrates the eardrum, and the vibrations are mechanically amplified by three tiny bones (hammer, anvil and stirrup) and transmitted to the cochlea. Inside it, thousands of hair cells convert this movement into electrical impulses.

These signals travel along the auditory nerve to the brain, where a complex process unfolds: specialized areas such as the auditory cortex decode the objective properties of sound (volume, pitch, timbre), while the limbic system associates them with our experiences and memories, generating an emotional response. This is the moment where a physical process becomes a subjective experience, through neurochemical reactions such as the release of dopamine.

Living the energy of music

If music’s energy is such a powerful physical phenomenon, its fullest expression lies in the collective experience: concerts and festivals. It’s here that sound waves become a tangible connection between people, uniting thousands of voices and emotions in a single moment. Truly understanding this process means recognizing the value of these experiences. It is this understanding that drives Plenitude’s support for live music, our concrete commitment to major festivals and events across Italy and Europe.

This summer, together with Aperol, we brought our solar-powered Recharge Stations to the Kappa Futur Festival in Turin and the Locus Festival in Bari, a journey that will culminate in September with Spring Attitude in Rome, offering the public a more sustainable way to recharge their devices.

Likewise, the KISS KISS WAY summer tour by Radio Kiss Kiss featured our initiative “The Best from the sun”: a sunscreen dispenser powered by solar energy, combining care for people with a passion for music.

Our support for musical culture is an ongoing project, ranging from major international stages like Primavera Sound in Barcelona, to unique events that unite music and local identity, such as La Prima Estate in Versilia, and projects like Festivalle, hosted in the Valley of the Temples in Agrigento, Italian Capital of Culture 2025, all the way to the Sanremo Music Festival.

It’s a wave of energy we’ve helped set in motion, and one that as Plenitude, we’ll continue to carry forward in the future.

Learn more about our commitment: https://corporate.eniplenitude.com/en/about/partnerships-and-events/musical-events