Pull chord progressions from any reference track. Find the key so you can transpose to your vocal range. Capture a tempo by tapping your phone screen the second the idea hits.
Songwriting moves at the speed of inspiration. SignalKey turns the references in your head into chord charts, keys and tempos in seconds — so the song idea you had in the car still exists when you sit down at the piano.
Every tool below is free, no signup, no watermark. Click any card to open it.
Drop a reference track and get the chord chart. Triads, 7ths, sus, add, slash voicings — with inversions reported.
Find the key of a song you're covering, then plan the transposition to your vocal range.
Drop the reference track ±6 semitones to a key that fits your voice. Tempo stays untouched.
Slow a complex passage to half-speed for transcription, or speed up a demo to feel the energy.
Lock a tempo by tapping your phone — useful when you hear the next single in a coffee shop and need to remember it.
Compound time signatures (6/8, 9/8, 12/8) and triplet subdivisions. Match your songwriting to the feel you need.
How songwriters move from inspiration to a finished demo.
You hear a song with the exact mood your bridge needs. Tap Tempo gives you the BPM. Chord Finder gives you the progression. Key Finder gives you the key. All three in under a minute.
The reference is in F# major — too high. Pitch Shifter drops it to D major where your vocal sits. Tempo unchanged. Now you can sing along while you write.
There's a piano line you can't quite catch. Tempo Changer takes the audio to 50% speed — same pitch, half the tempo. Transcribe at your own pace.
Use the chord chart and key as the backbone. Metronome locked to the captured tempo. Track a guide vocal. Export the chord chart as PDF for your co-writer.
“Wrote three sketches in one weekend by stealing the chord progression off three references — re-harmonised, fresh melody on top, my song.”
— Pop / R&B songwriter workflowChord Finder displays the progression in standard notation on screen. PDF export is on the roadmap; for now you can copy the chord names directly into your writing tool.
Drop a track and see the full analysis pass — BPM, key, Camelot, stems, MIDI, LUFS — in one go.