In “Berghain,” one of the songs from Rosalía’s latest album, there are passages that may surprise listeners. Her voice moves away from the usual pop register and approaches a style reminiscent of opera: the phrasing becomes broader, the vibrato more sustained, and the sound more uniform and projected.

The key lies not only in how this voice is produced, but in how it reaches the audience. In Rosalía’s concerts, the voice is captured with microphones, processed electronically, and reproduced through loudspeakers. In a traditional operatic performance, by contrast, no amplification is used: the voice must be clearly heard throughout the entire venue on its own. This difference completely transforms the role of acoustics in the musical experience.

The Acoustics Behind Musicians’ Frustration

Many musicians have experienced a well-known frustrating situation: after hours of rehearsal and preparation, they go on stage and the result is not what they expected. Not because they perform worse, but because they cannot hear themselves properly or the audience cannot clearly perceive what they are playing. In many cases, the problem is not musical, but acoustic.

What reaches the listener is a combination of the direct sound from the voice or instrument and how it is reflected by walls, ceilings, and other surfaces. This interaction can be understood through two fundamental effects: the increase in sound level and the persistence of sound over time.

On one hand, sound reflections cause it to reach different areas of the hall with greater intensity and more uniformity. It is not only the sound produced by the singer or instrumentalist, but how the space redistributes that sound.

On the other hand, these reflections also make the sound persist for a certain time after the source has stopped emitting it. This phenomenon, known as reverberation, is an essential characteristic of any hall. A certain amount of reverberation adds continuity and richness to the sound, especially in operatic singing, as it enhances the sense of fullness and helps projection throughout the theatre.

If reverberation is excessive, however, its effects become problematic: the sound loses definition, details become blurred, and fast or articulated passages turn confusing. In addition, intelligibility—the ease with which sung text can be understood—is reduced. Under these conditions, both musical clarity and lyrics are compromised.

The Voice and the Hall: A Single Instrument

In opera, all these factors are crucial. The voice and the hall function as a single instrument that extends through space beyond the sound source. In fact, classical vocal technique has largely developed to adapt to these conditions: to project sound efficiently, maintain textual clarity, and take advantage of the theatre’s acoustic properties.

By contrast, in amplified concerts like Rosalía’s, the transmission channel is entirely different. The electroacoustic system (comprising microphones, digital processing, and loudspeakers) allows control over sound level and modification of timbre or spatial perception, recreating qualities reminiscent of opera, but under very different physical conditions.

This does not mean that acoustics becomes irrelevant; rather, its function changes. Instead of being the main transmission medium, it becomes part of a system where sound can be adjusted and technologically shaped.

For musicians, this has a clear consequence: musical performance cannot be separated from the space in which it takes place. The same repertoire can sound very different depending on the venue. A church with high reverberation may favor choral music but hinder fast passages. A modern concert hall with very little reverberation may offer greater precision but sometimes a less enveloping sound.

That is why professional musicians take time to become familiar with the acoustics of the place in which they will perform. Sound checks, adjusting dynamics, or adapting tempo are not minor details—they are an essential part of performance.

The Venue Is Also Part of the Music

The next time you attend a concert or an opera, try to pay attention not only to the musicians, but also to the space: the materials of the walls, whether smooth or irregular; the shape of the ceiling; the presence of curtains, wood, or hard surfaces; and how the sound changes depending on where you are located.

Many of these elements are part of the hall’s acoustic design. Irregular or angled surfaces help diffuse sound and prevent annoying echoes, while porous materials or thick fabrics absorb some of the sound energy and control reverberation.

Some modern halls also use adjustable devices and new acoustic materials inspired by wave physics—so-called acoustic metamaterials—to adapt the sound response depending on the type of music.

Music is not only created on stage: it is shaped by the space through which it reaches us.

Article published in theconversation.com: https://theconversation.com/rosalia-la-opera-y-la-fisica-que-se-esconde-en-la-acustica-de-los-conciertos-282649

Author: Rubén Picó Vila, expert in musical acoustics from the Gandia Campus of the Polytechnic University of Valencia.

Image: A clip from the music video of ‘Berghain’ by Rosalía. Rosalía/Youtube