neirocca sound-first music theory

Analysis & Transposing

Key Finder

Enter the chords from a song to estimate likely keys and see match strength. A practical starting point for ear-copying and progression analysis.

Enter chords

Enter chord names separated by spaces (e.g., C Am F G7)

Result
Enter chords

What is this tool?

A key detector that takes the chords in a song and figures out which key (major or minor) they most likely belong to. You'll see a match score and which diatonic chords each input chord corresponds to.

When it helps

  • Confirm the key of a song you transcribed

    Enter the chords you heard and instantly see whether the song sits in a major or minor key — and which one.

  • Charts without a key signature

    If a lead sheet or lyric site skips the key, this fills in the gap and links you straight to the diatonic chord table.

  • Understand your own writing

    Feed in a progression you're drafting to see what key it naturally implies — handy when you're between two tonalities.

How to use

  1. 1 Pick 'Text input' or 'Select input' in the top bar.
  2. 2 For text input, type chord names separated by spaces (e.g. C Am F G).
  3. 3 For select input, tap '+ Add' to choose a root and quality, then add it to the list.
  4. 4 Press 'Analyze' in the bottom dock; the most likely keys appear ranked by match score.
  5. 5 From each result card, jump into 'View diatonic' or 'View scale' to explore that key in depth.

Related Tools

Related Articles