How to find the key of a song (by ear)
March 25th, 2008If you know the “key” of a song, you’ll know which notes the melody uses, and which chords to play. Finding the key of a song is the first step of transcribing.
Playing from sheet music, you can find the key by looking at the key signature. But if you’re playing by ear, you’ll have to do some experimentation.
First, I play along with the song and try to find the scale that matches the melody.
There is a wonderful program called Transcribe! that can help you with this. It can loop endlessly through sections of the song and even slow the music down while keeping it at the same pitch. Very handy!
Most songs are in a major key and there are 12 possible major scales. If you know these scales by heart it shouldn’t be too much of a problem to find the right one.
For example, if I press the A on the piano and it sounds wrong with the music, then I can exclude all the scales that have the A tone. I know the song will be in one of the following keys: Eb, Ab, Db, F#, or B.
Now I can restrict my search to the tones of these five scales. Usually after trying a few tones you’ve found the right scale.
I already mentioned in a previous article that the same scale is used for a major key and its relative minor key. For most songs you can assume they are in a major key, but some songs are in a minor key. If you’re not sure, you’ll have to look at the chords for additional clues.
Usually the very last chord of the song — and often also the very first chord of the song — will be the home chord, or the I chord. That is, the chord that names the key. If a song ends with the E chord, then chances are it is in the key of E.
You can verify this by playing the E chord along with the song — most of the time it should sound good. In the spots where it doesn’t sound good, you’re supposed to use another chord from the key of E. (Typically the V7 chord, in this case B7. Or the IV chord, in this case A.)
If you found the E major scale works for (most of) the song but E chord sounds wrong somehow, then try C#m, which is the relative minor of E. If C#m works, then the song is in a minor key.
In a similar vein, you can listen for the final tone of the song. Just like the final chord tends to be the chord that names the key, so is the final tone. Of course, there are exceptions but 95% of the time this will be true.
Here is another tip that I found on the internet some time ago:
- Sing along with the song for one or two lines while it’s playing, and then:
- Sing DO-RE-MI-FA-SOL-FA-MI-RE-DO.
- The final “DO” you land on is the key you are trying to find.
It’s not an exact science, but it works. 