Common Pulse
Common Pulse is a musical field notebook that helps people move from a short recording to an editable, participatory understanding of rhythm.
Core trick
Quantizes detected sound onsets into an editable grid and exports MusicXML, keeping the original recording beside the draft transcription.
Description
Common Pulse is a musical field notebook that helps people move from a short recording to an editable, participatory understanding of rhythm. A researcher, educator, or learner can record clapping, voice, or an isolated instrument; review detected sound events in a Time Unit Box System (TUBS) grid; edit the cycle and tempo; see equivalent unpitched Western rhythmic notation; and export MusicXML. They can attach time-linked observations, practice a part by tapping or clapping, and save the notebook locally.
The project treats automated transcription as a draft, not an authority. The recording stays available alongside the quantized grid, and the app makes clear what is measured, what a researcher has named, and what is an interpretation. It does not infer cultural origin or instrument identity from a rhythm.
With Astra connected, Common Pulse turns field notes into a research conversation. An ethnomusicologist can dictate a note, ask Astra to explain an edited pattern or make a bounded correction, and search for cited performance examples—including YouTube when available. Astra is instructed to distinguish documented sources from possible comparisons and to avoid unsupported cultural claims.
README excerpt
# Common Pulse A working hackathon prototype for musical field recording, editable rhythmic transcription, contextual research, and participation. Built with React, Vinext, Web Audio, and the OpenAI Responses API using `gpt-6-astra`. ## Use it - Record up to 60 seconds, upload an audio file up to 20 MB, or use the original synthetic practice sketch. - Review the first cycle in TUBS, change cells, name parts, mute parts, and play the resulting pattern. - Set cycle length and tempo. Three equal grid pulses correspond to one displayed BPM beat. Rebuild the detected part after a tempo change if desired; original onset timestamps are preserved. - View equivalent rhythmic Western staff notation and export MusicXML. - Inspect candidate section boundaries based on changes in signal energy. - Type timestamped observations or connect an OpenAI API key and dictate a field note. Dictation uses `gpt-transcribe` for speech, not musical note transcription. - Ask Astra to interpret measurements and field notes, explain a pattern, or apply a correction. A validated response can update the rhythm. Concurrent manual edits are preserved. - Search the web with Astra for documented performances, with inline citations and embedded YouTube videos when cited video URLs are available. Videos that disallow embedding can still be opened using their source link. A direct YouTube search link works without an API key. - Practice a part for two cycles using the tap pad or space bar, with one-to-one onset