WaveRoll: JavaScript Library for Comparative MIDI Piano-Roll Visualization

TL;DR

WaveRoll is an open-source JavaScript library that facilitates the comparison and synchronized playback of multiple MIDI piano rolls in a browser, aiding in automatic music transcription evaluation.

Contribution

It introduces a novel interactive tool for visualizing and comparing MIDI outputs, enhancing model evaluation and error analysis in music transcription.

Findings

Enables synchronized visualization of multiple MIDI tracks

Helps identify pitch and timing discrepancies

Supports model evaluation in automatic music transcription

Abstract

WaveRoll is an interactive JavaScript library that enables comparative visualization and synchronized playback of multiple MIDI piano rolls on a browser. It addresses a specific evaluation need in Automatic Music Transcription (AMT), contrasting multiple MIDI outputs produced from the same input. The library displays multiple MIDI tracks on a single, time-aligned grid with synchronized audio, allowing users to compare pitch and timing, identify missed or extra notes, and observe onset and offset differences, as well as section-level patterns. We expect that such comparisons would assist in model evaluation and error analysis, and help readers to understand the model behavior better. The open-source library is available at https://github.com/crescent-stdio/wave-roll