Magic Chords is a 100% free web app for musicians and producers. Upload audio or paste a URL to detect chords, key, and tempo, then play along with synchronized guitar, piano, and bass diagrams. Transcribe lyrics with AI in 9+ languages (Whisper), transpose to any key instantly, and export everything: MIDI, PDF, iReal Pro, Guitar & Bass Tabs — 9 formats. No paywall, no signup, built by a musician for musicians.