Film music is usually something that creeps in through the back door. It whispers, it nudges, it tries to be invisible while telling you what to feel. "Sobre las Olas", instead, kicks the door wide open and says: “Forget the orchestra. Forget the violins. The human voice was here first”.

Trondheim Voices, the ever-restless Norwegian ensemble of improvising singers, teamed up with sound designer Asle Karstad and Mexican-Spanish director Horacio Alcalá to attempt the unthinkable: score an entire feature film using nothing but improvised vocals, filtered, looped and reshaped in real time with custom-built “Maccatrols”. The result is less soundtrack and more geological force - like tectonic plates made of breath and syllables, grinding until landscapes emerge.

The music doesn’t decorate "Sobre las Olas". It "inhabits" it. In tracks like "Pure Soul" and "Angel Farewell", the voices move like winds through the fictional island of Magdala, sometimes gentle, sometimes cutting, always impossible to pin down. "Love Letter to Carmen" lasts barely more than a minute, yet it feels like a memory excavated from someone else’s dream. "David Lynch would probably nod approvingly, then ask for the number of their sound engineer".

There’s a strange irony here: despite being thoroughly futuristic in its use of live electronics, the record sounds primordial. These are not melodies or arias; they are incantations, echoes of something that might have existed before language itself. You can almost believe Alcalá when he says the voices came first and the film followed, as if Magdala’s myths had been sung into existence.

Not every listener will find comfort here - this is not music that hugs you; it stares at you until you reveal your own secrets. Yet, there’s also serenity: in "Lake Love" or "Sky", voices drift and expand like fog lifting over water, reminding us that fragility and enormity are sometimes the same thing.

"Sobre las Olas" is a gamble, yes. But it pays off beautifully. Where other soundtracks are content to be invisible scaffolding, this one is the building itself: cathedral walls made of resonance, foundations laid in whispers, arches rising in loops of air. A risky experiment, but one that makes the listener believe again in the simple, terrifying, miraculous power of the human voice.