# Audio Chord Progression Detector Estimate an audio file's chord sequence locally and download CSV, JSON, SVG, and method notes in one ZIP. > Canonical page: https://elysiatools.com/en/tools/audio-chord-progression-detector - **Category:** Media - **Keywords:** chord detector, chord progression, HPCP, audio analysis, music theory, chroma ## Overview FFmpeg decodes up to three minutes of audio to bounded mono PCM. Overlapping Hann spectra are folded into HPCP-like pitch classes, compared with common chord templates, and temporally smoothed to reduce flicker. The result is an approximate MIR guide for listening and annotation, not score-level ground truth. ## Inputs - **Audio File** (file) - **Analysis Resolution** (select) - **Minimum Chord Duration (s)** (number) - **Confidence Threshold** (number) ## When to use - You have a WAV, MP3, FLAC, OGG, OPUS, M4A, or AAC clip and want a first-pass chord timeline without scoring the track by ear. - You need CSV, JSON, and SVG exports of estimated chord regions for annotation, teaching, or arranging a loop. - You want to trade analysis resolution and minimum chord duration against flicker, using a confidence threshold to drop weak matches. ## How it works - Upload one audio file (up to 100 MB). FFmpeg decodes up to three minutes to bounded mono PCM. - Choose Quick, Balanced, or Detailed analysis resolution, then set minimum chord duration (0.5–4 s) and confidence threshold (0.1–0.8). - Overlapping Hann spectra are folded into HPCP-like pitch classes, compared with common chord templates, and temporally smoothed to reduce flicker. - Download a ZIP with CSV and JSON timelines, an SVG view of the estimated progression, and README method notes. ## Use cases - Map a four-chord pop loop into timed C, Am, F, and G regions for charts or DAW markers. - Inspect short chord changes with detailed resolution and a 0.5 s minimum duration. - Export JSON/CSV chord timelines plus an SVG overview for teaching, lead sheets, or annotation. ## Frequently asked questions ### What audio formats can I upload? WAV, MP3, FLAC, OGG, OPUS, M4A, and AAC, plus other audio/* files, with a 100 MB limit. Analysis uses at most the first three minutes. ### Is the output an exact transcription? No. It is an approximate MIR guide from chroma/HPCP template matching. Use it for listening and annotation, not as score-level ground truth. ### What do Quick, Balanced, and Detailed change? They set analysis resolution. Detailed keeps finer transition boundaries; Quick is coarser. Balanced is the default for typical pop-style loops. ### How do minimum duration and confidence affect labels? Minimum chord duration (default 0.7 s) merges short flickers. Confidence threshold (default 0.2) drops weak template matches before smoothing. ### What is inside the ZIP? CSV and JSON chord timelines, an SVG of the estimated sequence, and README method notes describing the local analysis. ## Related tools - [Audio Melody Contour Extractor](https://elysiatools.com/en/tools/audio-melody-contour-extractor): Extract a dominant melody path from audio and export MIDI, note events, a pitch contour, SVG, and JSON in one ZIP. - [Audio Codec Swap](https://elysiatools.com/en/tools/audio-codec-swap): Change the codec of an audio file within a chosen output format - [Audio to Multitrack MIDI (Draft)](https://elysiatools.com/en/tools/audio-to-multitrack-midi): Split a full mix into stems (drums/bass/other/vocals) and transcribe each to MIDI — a multi-track starting point for transcription - [Batch Audio Converter](https://elysiatools.com/en/tools/audio-batch-converter): Convert multiple audio files between different formats like MP3, WAV, FLAC, AAC, OGG, Opus with quality settings and batch processing - [Audio to Text Transcriber (AI)](https://elysiatools.com/en/tools/audio-to-text-transcriber): Transcribe speech from audio (wav/mp3/m4a/flac/ogg/webm/aac) to text, SRT, VTT or JSON using the grok-stt AI model. Up to 10 minutes. - [Audio Resample](https://elysiatools.com/en/tools/audio-resample): Change the sample rate of an audio file (e.g., 44.1kHz to 22.05kHz) - [Audio Format Converter](https://elysiatools.com/en/tools/audio-converter): Convert audio files between different formats like MP3, WAV, FLAC, AAC, OGG with quality settings and volume adjustment - [Audio Channel Resample](https://elysiatools.com/en/tools/audio-channel-resample): Change the number of channels (mono/stereo) while keeping the same format ## Samples - [Copyright-Free FLAC Audio Samples](https://elysiatools.com/en/samples/flac-samples): Lossless FLAC audio samples for testing and development, mirrored from MP3 set with nature sounds and meditation music - [Copyright-Free MP3 Audio Samples](https://elysiatools.com/en/samples/mp3-samples): Collection of royalty-free audio samples for testing and development purposes including nature sounds, meditation music, and ambient audio - [Copyright-Free WAV Audio Samples](https://elysiatools.com/en/samples/wav-samples): Uncompressed PCM WAV audio samples for testing and development, mirrored from MP3 set with nature sounds and meditation music - [Copyright-Free M4A Audio Samples](https://elysiatools.com/en/samples/m4a-samples): Apple iTunes compatible M4A audio samples with AAC encoding, optimized for quality and file size balance ## Related content - [Audio Measurement and Inspection Tools](https://elysiatools.com/en/hubs/audio-analyze): Compare loudness, dynamic range, peak, BPM, key detection, spectral inspection, and metadata review tools in one hub for audio analysis. - [Data Quality, Dedupe, and Anomaly Detection Tools](https://elysiatools.com/en/hubs/data-quality-anomaly-workflows): Profile CSV/JSON datasets, compare spreadsheet versions, find duplicates, outliers, missing-value issues, referential breaks, and time-series anomalies in one data-quality workflow hub. - [Audio Encoding and Format Conversion Tools](https://elysiatools.com/en/hubs/audio-convert): Compare audio format conversion, bitrate changes, sample-rate conversion, codec swaps, and export tools in one hub for delivery and archive workflows. - [JSON Interchange and Format Translation Tools](https://elysiatools.com/en/hubs/json-convert): Compare JSON conversion tools for CSV, YAML, TOML, GraphQL, XML, Markdown, Excel, BSON, EDN, and related structured formats in one hub.