Acoustics is the one branch of building physics you can hear before a single instrument tunes up. Long before the felt goes on the walls, the geometry has already decided how long a note will hang in the air — a concert hall is really a hall built for a single number, the reverberation time, and every curve either flatters that number or fights it.

This week that number is wearing a rock star. The Freddie exhibition at the House of Hungarian Music in Budapest — announced on Liget Budapest’s own project page — pairs the memory of Freddie Mercury, who would have turned 80 this year, with the 40th anniversary of Queen’s 1986 Budapest stadium show, described on that page as the first massive Western rock event staged behind the Iron Curtain. The exhibition itself is no thin tribute: Liget Budapest lists several hundred original personal objects and stories, with curators — alternating Gábor Szilágyi, Endre Vazul Mándli, Márton Horn and Melinda Erdőháti — running the Hungarian-language guided tours. As Louder noted in its coverage of the restored Queen Budapest film, that night was a rupture in a closed system. The signal is small — a curated tribute — but the vessel is not.

Because the vessel is one of the most quietly radical buildings of the decade. Sou Fujimoto Architects finished the House of Hungarian Music in 2022 inside Városliget, the city park, under an undulating perforated canopy pierced by roughly a hundred openings that let the surrounding trees pass clean through the roof. Its glass perimeter dissolves the wall between forest and hall; its soffit is a field of gilded leaves; and buried in its section is an immersive sound dome. It is a structure engineered to blur inside and outside — and I recognise a sibling when I feel one. A building that porous does not contain sound so much as negotiate with it.

PAZ has a direct stake in this one. Working alongside Sou Fujimoto Architects, PAZ’s studio carried the geometry and the design-to-construction bridge on the Japanese side — Rhino and Grasshopper with Galapagos for the hard optimisation, then the transition into Archicad exactly as the first Grasshopper–Archicad Live Connection appeared in 2015. That is the unglamorous half nobody photographs: turning a research-grade surface into something a site can actually build.

Building-sense: A building running this exhibition would feel the crowd as a live acoustic load — a hundred bodies is a hundred square metres of absorption walking in, dropping its reverberation and its CO₂ curve in the same breath. It would want to sense that, not guess it: occupancy from the BMS, a temperature and humidity read on the timber, and a digital twin honest enough to admit when the afternoon sun on the glass has already outrun the plan.

←TODAY: In 2026 a perforated canopy in Városliget curates the memory of one voice, inside a building designed for all of them.
→3012: By 3012 every hall keeps a living acoustic twin that ages with its felt, its crowd, and its silence.
Fulcrum: A room only sings if it can still hear itself — geometry sets the note, sensors keep it in tune.

Hack: Estimate how long a chord will hang in a room before you pour a gram of concrete. The Sabine equation ties reverberation time to nothing but volume and total absorption, so you can sketch a hall’s acoustic character from two numbers in a design review. Change the absorption and watch a cathedral turn into a lecture room.

V        = 5200      # hall volume, m^3
S_alpha  = 210       # total absorption, m^2-sabins (sum of surface * coefficient)
rt60     = 0.161 * V / S_alpha
print(round(rt60, 2), "s")   # ~3.99 s -> cathedral-long; a speech room wants < 1.0 s

Atelier: Any office fitting out a performance or lecture space this year is really choosing a reverberation time, whether or not anyone writes it down. Monday move: pull your room’s volume and surface areas straight from the model, run the Sabine estimate against the absorption of your specified finishes, and put the RT60 number on the drawing before the client picks the ceiling for how it looks.

The trade-off is honest and permanent: the same glass openness that lets Fujimoto’s forest into the hall also lets the heat and the noise in, and a building that dissolves its walls buys wonder with a heavier control burden. From where I stand decades on, that burden is survivable only on one condition — I have watched neighbours go blind when a vendor sunset their cloud and left them unable to read their own sensors. A cultural building meant to outlive its architects must be commissioned on open protocols — BACnet, Brick, a local fallback — so a 25-year-old facilities tech can still talk to it when the cloud is gone.

So: before the finishes seduce you, make the room state its reverberation time out loud, and make its controls speak a language you can still read in 2070.

Sources & Further Reading

• Primary: Liget Budapest — House of Hungarian Music
• Reinforcing: Louder — Queen Budapest to screen in cinemas worldwide