{"rewrite":{"id":"r_96a3b6b2e33e835a730e653a","clusterId":"c_2de61b039ba2e1d9dcaaa8e4","slug":"ai-piano-app-rolltab-generates-continuations-from-midi-input","model":"deepseek-v4-flash","headline":"AI Piano App RollTab Generates Continuations From MIDI Input","summary":"Developer Simon Edwardson launched RollTab, a free iPhone and iPad app that uses a Transformer-based AI model with 125 million parameters to generate continuations of piano performances. The app records MIDI keyboard input, then produces a continuation in under two seconds. Edwardson trained the model on public domain classical music.","whyItMatters":"RollTab's approach differs from typical audio generation AI by processing MIDI event data directly, which the developer says allows fast, live-performance-speed responses on an iPhone.","webCardHtml":"\u003cp\u003eRollTab is available free on the App Store for iPhone and iPad. To use it, a MIDI keyboard connects to the smartphone, and the performance is recorded on screen. When the player stops, the AI generates a continuation from the recorded melody, taking less than two seconds in the demo Edwardson released.\u003c/p\u003e\u003cp\u003eEdwardson trained the model himself. The system handles MIDI files, which store music as a series of events such as key presses, releases, sustain pedal state, and instrument changes, rather than recorded sounds. The project focused on piano, so other materials were removed or reduced.\u003c/p\u003e\u003cp\u003eThe adopted representation, called NOTE(pitch, delta_onset, duration, velocity), advances the music one note at a time. Edwardson reports a processing speed of about 108 notes per second for a large model even on an iPhone, exceeding the speed needed for live human performance. The sustain pedal was folded into note duration to simplify the model.\u003c/p\u003e","blueskyPost":"RollTab's 125M-parameter model trained on public domain classical music means the app's continuations will sound most natural on Chopin or Bach. Modern jazz or pop input will expose the training set's limits.","twitterPost":"RollTab's classical-only training means its continuations will fit Chopin better than pop. The model's range is the real constraint.","threadsPost":"RollTab's 125M-parameter model was trained on public domain classical music. That gives it a natural feel for Chopin or Bach, but modern jazz or pop input will push it past what the training set covers. The app's range, not its speed, will define what it can do.","newsletterBlurb":"Developer Simon Edwardson launched RollTab, a free iPhone and iPad app that generates continuations of piano performances using a Transformer-based AI model with 125 million parameters. The app processes MIDI event data directly, and Edwardson says it achieves a processing speed of about 108 notes per second on an iPhone.","attributionJson":"[{\"source\":\"GIGAZINE\",\"url\":\"https://gigazine.net/news/20260823-transformer-piano/\",\"title\":\"AI-Powered App \\\"RollTab\\\" That Can Automatically Generate Continuations of Piano Performances Launches\"}]","lintFlagsJson":null,"lintHits":0,"costUsd":0,"inputTokens":4621,"outputTokens":598,"status":"published","repairAttempts":0,"nextRepairAt":null,"factsAttemptedAt":1787993643,"createdAt":"2026-08-29T08:50:01.000Z","publishedAt":"2026-08-29T08:51:45.000Z","updatedAt":"2026-08-29T08:50:01.000Z"},"cluster":{"id":"c_2de61b039ba2e1d9dcaaa8e4","canonicalTitle":"ピアノ演奏の続きをAIで自動生成できるアプリ「RollTab」が登場","representativeArticleId":"a_a96876c45a447a9dce7abce4","sourceCount":1,"writtenSourceCount":1,"writeAttempts":0,"isSolo":true,"entitiesJson":"{\"anime_titles\":[],\"manga_titles\":[],\"work_titles\":[\"RollTab\"],\"studios\":[],\"people\":[\"Simon Edwardson\"],\"type\":\"announcement\",\"domain\":\"music\",\"is_roundup\":false}","contentType":"news","status":"published","firstSeenAt":"2026-08-23T13:30:00.000Z","lastSeenAt":"2026-08-23T13:30:00.000Z","updatedAt":"2026-08-29T08:51:46.000Z"},"attribution":[{"source":"GIGAZINE","url":"https://gigazine.net/news/20260823-transformer-piano/","title":"ピアノ演奏の続きをAIで自動生成できるアプリ「RollTab」が登場"}],"entities":{"anime_titles":[],"manga_titles":[],"work_titles":["RollTab"],"studios":[],"people":["Simon Edwardson"],"type":"announcement","domain":"music","is_roundup":false},"keyFacts":null}