It’s the sound that hits you. Your chest trembles with subtle power far beyond that of the crude thud of bass in a club, and shrill notes ply the very limits of your hearing.

Live orchestral music is breathtaking, especially when you’re hearing it in Studio One at Abbey Road Studios. With fabric baffles hanging in rows on the high ceiling and subtly angled sections of wall all around, the acoustics of this auspicious hall render every note as sharp as you’ve ever heard. It makes you realise how infrequently we hear music that isn’t amplified. This is music in its natural form: pure and vibrant.

And yet we’re hearing only half an orchestra. Today, woodwind and brass have convened for the second, and final, day of recording for Killzone 2’s 28 minutes of cutscene music. Later this evening, the choir will arrive to perform its parts before the session ends at 10pm.

Though 28 minutes doesn’t sound like much, it’s a punishing schedule for two days of sessions, and when we arrive in the late afternoon, they’re already running behind. The music’s composer, Joris de Man, who also wrote the scores for the original Killzone and PSP follow-up Killzone: Liberation as a founding member of Guerrilla Games, has had to hurriedly tweak the orchestration for sections that didn’t quite go to plan during yesterday’s session, in which they recorded the strings. And the conductor, Jon Williams, is finding the session particularly gruelling because he broke his collarbone only a couple of weeks previously.

But experienced from a balcony above the control room, it sounds incredible. Even without the strings and choir in place, the music is full, angry and dramatic, with sharp trumpets punctuating phrases of the final piece of the day, The Helghast March.

On the other end of the scale are the loud, low, vicious barks of a cimbasso, but there’s room in the score for almost every instrument to take a role, from mournful oboe to processions of dramatic horns. Williams completes another take and quietly waits for de Man and the engineers in the control room to confirm over his headphones that all was well. The players relax.

Conservatively dressed and generally middle-aged, they’re all session musicians, and many play principally for the London Symphony Orchestra. You can’t help but wonder what they think about playing music for a videogame. Eventually, with two minutes to go until the wind section’s session time is up, the control room confirms it’s a wrap.