To recap:
- When working out the key of a tune, you need to work out two things – the key note and the type of key or mode.
- The key note will be the home note – the note that finishes a tune like a full stop.
- The type of key or mode will be revealed by looking at the rest of the notes of the tune – i.e. which notes are sharpened or flattened. Refer to the chart further down this post.
When looking at a tune as a whole, start off playing through the tune to determine the note that you would finish on 99% of the time. This note will be the key note, the last note being the best guide. If E is the home note, the tune will be in the key of E something. If D is the home note the tunes will be in D something.
Say the last note is A you now have 4 choices of key. It could be A major, A mixolydian, A dorian or A minor. These keys have 3, 2, 1 and no sharps, respectively. See chart below.
Look at the rest of the tune and find out which notes (if any) are sharp. If the only sharp notes in the tune are F and C, then you can be pretty sure that the tune is in A mixolydian. If there are no sharps, then it will be A minor. If there are C sharps and B flats, you’ve gone for a tune that is beyond the geographical scope of these short articles!
Below are 4 examples, all in different keys. They all share the same key signature, though – 2 sharps.
The last note of each example gives us the key note.
The chart below shows all the commonly used Major, Minor, Mixolydian and Dorian keys, plus a few less-commonly used ones.
When it comes to music, rules are often broken and exceptions will crop up regularly. One of the most confusing is when a tune changes key. We’ll look at a couple of examples in the next post.