22 October 2026 · a listening experiment · Built with Claude
Someone is playing a bowed baritone instrument on the ground. You are standing a little way above. On Earth, climbing changes nothing about what you hear. Make the planet heavier and the air thins so fast with height that altitude gets a sound: first the music fades as you rise, then its bass stops being able to reach you at all. Press Listen: each phrase is played twice, once from the player's spot and once from yours.
Drag to climb. Shading is air density; lines are metres, heavy lines are 3 m storeys. The ring shows where you're listening from right now.
Gravity piles air up at the bottom. On Earth the pile is 8 km tall, so a tower is nothing. At 650 g the pile is 13 m tall; at 40,000 g it is 20 cm. A sound wave climbing into thinner air keeps its energy but carries less and less pressure, which is what your ear measures. So the music gets quieter with height, by a fixed number of decibels per metre.
Layered air has a floor pitch. Below a certain frequency, about γg / 4πc, the layering stops sound from travelling upward at all: it just fades out within a metre or so. The higher you stand, the more of the bass above that floor has faded too. On a heavy world, the bottom of the spectrum is an altimeter.
And that is why they'd move sideways. By the time gravity is strong enough for the air to sound like altitude, a single storey is a cliff of silence. The audible world is a metre or two thick. Up is for priests and outcasts.
Air at 20 °C, constant temperature with height, sound going straight up, linear acoustics. Scale height H = c² / γg; floor pitch f = c / 4πH; pressure falls as exp(−z / 2H); a pitch below the floor fades as exp(−z·√(ωₐ² − ω²) / c). The climb is rendered as an impulse response and the music is convolved with it, live. Temperature layering, absorption and spreading loss are left out.
The baritone is an invented bowed-string instrument, not a recording: a sawtooth (the bridge force of a bowed string) through a set of body resonances, with bow noise, slurs, bow changes and delayed vibrato. If you have a phrase of your own, use the recording picker above; it stays in your browser.