ChordProgressions.org vs ChordU

ChordProgressions.org is a free browser studio for creating, hearing, analyzing, customizing, and exporting chord progressions for guitar and piano. Its tools include generators, builders, finders, identifiers, analyzers, and transposers. Guitar shapes and piano voicings can be adjusted for tuning, capo position, difficulty, inversions, and fingering. Theory views show Roman numerals, Nashville numbers, chord functions, cadence points, borrowed chords, and an estimated key with confidence. The studio accepts MIDI input and imports MusicXML, project files, and plain-text chord sheets. Browser audio analysis creates an editable chord timeline with a confidence score. Exports include MIDI, WAV, chord-chart PDF, PNG and SVG diagrams, plain text, CSV, JSON, MusicXML, and share links. Projects autosave on the device, and imported files are read locally. Practice tools loop progressions with metronome and count-in, plus ear and playing exercises in every key.

ChordU identifies chords in audio and aligns them with musical notation. Users can also find a song on YouTube, copy its link and search for it in ChordU. A song may have simplified, advanced, bass or edited chord arrangements, as well as treble-clef and bass-clef note versions. Chord diagrams cover guitar, piano, ukulele and mandolin. On the website, users can obtain PDF chord and note sheets, MIDI files and synthesized notes in WAV format. MusicOnly mode provides controls for vocals, bass, drums and other instruments, and can export a mixed audio download. Local music uploads and MusicOnly for those uploads require Premium; Premium also permits chord downloads without a stated monthly limit. The Free plan has limited access, while Premium costs $5.00 per month. ChordU is available on Android, iOS and the web. Its terms limit song and chord use to personal, non-commercial purposes.