What does “key” mean?

Over the years, I’d say this was one of the most common questions I’m asked about traditional tunes.  Most people who ask it will accept the answer I give, but some want to go deeper and understand more about keys.  Of these, the majority begin to glaze over as soon as I start mentioning words like Mixolydian, mode, natural minor, etc.  It is quite a difficult thing to get your head round at first, so here I am attempting to offer a user-friendly guide to working out the key of most folk tunes (at least, most tunes from the British Isles, North America and large parts of Europe).

Possible reasons you might want to know this information are:

• You want to let guitarists or other accompanying instruments know what key you are playing in, so they can make a stab at playing the right chords.
• Knowing the key of a tune or song will be very helpful when it comes to improvising your own variations or solos.
• Many musicians want a deeper knowledge of the music they are playing.

What does the word “key” mean?

If we say a tune is in the key of E major, it means that the tune is based around the note E (the key note) and the other notes involved (and the way they relate to the key note) will give the feeling of major.  If the tune is in the key of E minor, E will still be the key note, but the other notes will be subtly altered to give a minor feeling.

The key note can be described as the “home” note.  The note to which the tune keeps returning.  If you play a tune and finish it, the note that finishes it off, like a full-stop, will be the key note.  So, if the tune feels like it is finished when you play G, then the key will be G something (major or minor – there are mixolydian or dorian in the case of music from the areas I’m covering).

Major, minor, mixolydian and dorian are modes, or types of key.  Major is also known as Ionian and Minor as Aeolian or natural minor.

Most tunes will be in one of these modes.  It’s confusing to have more than one name for these modes, but we’re stuck with it, unfortunately.  Here are a few practical points on these modes, plus a description of the feel of each mode.

Major (bright and cheerful) – many folk musicians won’t use this term, and far less will use the term Ionian.  It’s more common to just say “this tune’s in A” or “this one’s in D”.  This means major.  It’s just so common to have tunes in major keys, that most people don’t bother saying major.

Mixolydian (mostly happy, but slightly scarred) – closely related to major, I describe this as major with a hint of minor about it.  Most people don’t use the term mixolydian, and just refer to it as major.

Minor (mournful) – This is less common than you’d think, most minor tunes being in the very similar dorian mode.  Also known as Aeolian, but nobody uses this term.

Dorian (sad, but with hope for the future) – closely related to minor, say minor with a hint of major.  Most people wrongly describe Dorian as minor, but pointing that out in a session might be seen as pedantic!

When describing the key of a tune, it’s normal to say it’s “in G” or “in D minor”

More in-depth information on keys in the next post