Gary Provost taught writers that sentence length is rhythm: vary it, and the writing sings. This lab makes that audible. Every sentence gets a highlighter color for its length — and a musical note to match. Read the masters, then listen to your own writing.
Every sentence is measured in words and painted by length. Color is never the only signal — each band has a name, a range, and its own sound in the synthesizer.
Scan the colors before you read the words:
The synthesizer turns structure into sound:
Eighteen public-domain voices in three wings — fiction, poetry, and nonfiction. Open a wing, pick a voice, and see its heat map, hear it played, and meet the author: bios and portraits load live from Wikipedia, and every full text is free online.
Type, paste, or upload your own writing. The heat map paints itself as you work — then send it to the Studio and hear whether it drones or sings.
Choose how your sentences sound. Presets set a whole mood; every dial below stays yours to change. The same settings play the Library, the demo, and your own writing.
All sound is synthesized live in your browser with the Web Audio API — nothing is downloaded, streamed, or sent anywhere. Use the Export section to save your composition as a real audio file.
The truest tempo is a human voice — yours. Record yourself reading a passage aloud and tap the spacebar at the end of each sentence. Your recording replays with the heat map lighting sentence by sentence, and the Booth shows exactly where your pace rose and fell.
Your microphone stays local: the recording never leaves this device, is never saved to disk unless you download it, and vanishes when you close the tab.
The heat map is a lens, not a verdict. Use these prompts to think about what you heard — in the masters and in yourself.
Which Library passage surprised you most when you heard it played? What did the music reveal about that writer's style that silent reading hid?
Pick two authors with very different heat maps. How does each writer use short sentences differently — and when does each one reach for a long sentence?
Look at your writing's heat map and listen to it play. Where does it drone on one color? Where does it already sing? Quote a specific sentence.
Name one concrete change you will make to your draft — combine two short sentences, break a long one, or build a crescendo. Why that move, and where?
Your report bundles your heat-mapped writing, your statistics, your Studio settings, and your reflections into one document. The audio download renders your composition as a real WAV file.
The analog packet is a 12-page printable: the same highlighter system with pen, paper, read-alouds, and writing prompts — the skill without the screen.
Everything you typed lives only in this browser (localStorage) until you export it. No accounts, no analytics, nothing leaves your device.