A free, browser-based drum simulator by Basel Ashraf: draw any shape and hear it as a real drum, with every frequency solved from your outline using finite-element physics — not sampled, and not AI.
Last verified · 2026-08-15 · by Moe Ameen
Eigendrum is a free web app, built by Basel Ashraf, that lets you draw any shape — or type it as a polar or parametric equation — and hear how a drumhead of that outline would actually sound. It answers a real mathematical question, Mark Kac's 1966 "Can one hear the shape of a drum?", by computing the sound directly from the geometry rather than playing a recorded sample. It runs entirely in your browser, needs no account and nothing to install, and is released under the MIT license.
The one thing to be clear about up front: despite how it is often shared, Eigendrum is not an AI tool. There is no model, no training data, and no generative guessing. It is a physics solver. A drumhead clamped at its rim can only vibrate in specific shapes at specific frequencies — the solutions of an eigenvalue problem — and Eigendrum solves that problem numerically. It covers your shape with a mesh of triangles, builds the finite-element stiffness and mass matrices, and finds the smallest eigenvalues of Kφ = λMφ; each eigenvalue gives a mode whose frequency is proportional to √λ. The frequency ratios come entirely from the outline, while absolute pitch depends on size and tension, and how fast each overtone fades depends on the material and the air.
The result is a small, precise instrument for exploring acoustics. You can strike the drum at different points and hear how the location changes the timbre, visualize up to 16 vibrational modes on their own or combined, and tune reference pitch, damping, and mallet properties. It is accurate too — tested against shapes with known spectra like circles and rectangles, it lands within about a tenth of a percent. It even ships the famous "Kac drums": two different outlines that enclose the same area and perimeter and share an identical frequency spectrum — so they sound the same despite their plainly different shapes, which is exactly the point of the "you can't always hear the shape of a drum" result. Eigendrum drew wide attention when it circulated in August 2026.
For a creator, the honest read is that Eigendrum is a delightful sound-design and teaching toy, not a music-production suite. It generates a single drum voice from a shape; it does not sequence a beat, layer a track, export stems for a DAW timeline, or publish anything. That is exactly where a content engine picks up.
Eigendrum makes something genuinely shareable — a screen recording of a shape becoming a sound, a mode animation, a "these two differently-shaped drums sound identical" reveal — but it stops the instant the sound plays. There is no way to caption it, cut it for a feed, wrap it in your brand, or put it in front of an audience. That is the seam [Kompozy](/) fills: it is a content generation and multi-platform publishing engine, and your Eigendrum capture is a perfect source clip for it.
Concretely: screen-record a session — draw the shape, strike it, sweep the modes — and drop that raw clip into Kompozy. It becomes a batch of finished posts from one source. Kompozy clips the long capture into vertical [Clipped Shorts](/glossary/content-repurposing), burns word-synced captions on, and reframes each cut to 9:16, 1:1, and 16:9 so the same demo ships to TikTok, Reels, Shorts, and a LinkedIn feed without re-editing. The "why do two different-shaped drums sound identical?" hook becomes a [Carousel Post](/glossary/output-buckets) rendered pixel-exact to your brand through [HyperFrames](/glossary/hyperframes), a Persona Shorts explainer voiced by your on-camera [persona](/glossary/persona-shorts), a [Blog Article](/glossary/output-buckets) on the math, and an email newsletter — all governed by one [Persona Brief](/glossary/persona-brief) so the voice stays yours across every format. Then Kompozy schedules and publishes the whole set across the eight social platforms plus blog and email on [Autopilot](/glossary/autopilot). Eigendrum designs the sound; Kompozy turns the moment of making it into a week of on-brand, published content.
No. Eigendrum is a physics simulator, not an AI model — there is no training data or generative guessing. It solves the eigenvalue problem for a drumhead of the shape you draw using finite-element analysis, so every frequency is computed directly from the outline rather than sampled or predicted.
Eigendrum was built by Basel Ashraf and is hosted at eigendrum.com. It is free to use with no account and nothing to install, runs entirely in your browser, and is released under the MIT license.
It covers your shape with a triangular mesh, builds the finite-element stiffness and mass matrices, and finds the smallest eigenvalues of Kφ = λMφ. Each eigenvalue is a vibrational mode whose frequency is proportional to √λ, so the drawn outline determines the frequency ratios and timbre.
No. It generates a single drum voice from a shape and lets you explore how it sounds; it does not sequence beats, layer instruments, or export a finished track. For full AI songs, tools like Suno or Treblo fit better — and a content engine like Kompozy turns any of it into published posts.
Screen-record a session and run it through Kompozy. It clips the capture into captioned vertical shorts, reframes each per platform, and can spin the same idea into a brand-exact carousel, a Persona Shorts explainer, a blog, and a newsletter, then schedules and publishes across the eight social platforms plus blog and email.