Modes and what they mean. Paul Colbert attempts (ha!) to explain where scales come from, and what the ancients did with the notes between C and B.

BLAME THIS one on the Greeks.

The most common scale that we all know is the Sound Of Music standard of Doh-Re-Me-Fah... etc. Plonked in front of a piano you'd start with a C then play all the white notes because it's dead easy on the fingers... C, D, E, F, A, B, C. Some of the white notes are right next to each other (E and F, B and C) and the rest are separated by a black note. Put another, more technical way, the E and F are a semitone apart (the smallest possible distance between two notes on the keyboard) and the rest are a tone (a semitone up to the black note, then another semitone on to the next white one). All very easy for those who had piano lessons where everything's in a straight line from left to right, less obvious for guitarists who have to jump around for it to make sense.

The pattern of semitone and tone gaps is what identifies each scale, its fingerprint if you like. That C run has the ever popular tone, tone, semitone, tone, tone, tone, semitone configuration. It's called The Diatonic Major Scale, and there's a lot of it about. You don't have to start with a C. You could choose any note, and as long as you kept to that gap pattern, you'd have a major scale - F, G, A, A sharp, C, D, E, F would supply a major scale in F, the A to A sharp and E to F supplying the two semitone jumps. OK, so 500 years of musical history in a couple of paragraphs.

Now supposing, for a moment, you were very rich. Nice isn't it? Now that's over, suppose you'd never heard of Julie Andrews and you sat down at the piano to play all the white notes, but this time started with the D - D, E, F, G, A, B, C, D. Same notes, no new ones, virtually an identical order, but the scale sounds quite different - no longer major, it's mournful, sad, slightly reflective. And the pattern of gaps has altered. Now we've got tone, semitone, tone, tone, tone, semitone, tone.

This we can put down to the Greeks who, having a much simpler grasp of musical wassname and, essentially, being rather old these days, used to get their tonal variety by producing different scales from just eight notes. Yup, the white notes on the piano. Black notes had they not. Oh no. They'd do it by starting each scale on a different note (giving you seven scales altogether) and calling them after famous tribes of the time. Fulham, Manchester City, Wolves, that sort of thing.

In fact they were the Ionian (C to C), Dorian (D to D), Phrygian (E to E), Lydian (F to F, and a great full back), Mixolydian (G to G), Aeolian (A to A) and Locrian (B to B). Exactly the same notes, but a quite different mood to each one, the Greeks would claim. And there's some truth in what they said.

When the Christians got hold of this much later on, the first thing they did was reverse the scales (the Greeks actually had them running downwards - maybe that was considered unGodly), rechristened them modes, and changed a couple of names. The list above is what we actually ended up with.

In the middle ages it was still the average musician's tinkering with the modal system that produced the melody of the day. By the 17th century they'd got hip to harmony (early music was distinctly monophonic) and the emphasis began to shift towards the idea of key signatures, and the principles of founding major and minor keys. You can't really say that modes have been rediscovered, after all the notes have always been there. But over the years musicians, whether classical, jazz or other, have occasionally become aware of what they're doing and then pursued a modal style.

The Ionian mode has come to be our major scale, and the Aeolian mode our minor one (tone, semitone, tone, tone, semitone, tone, tone). In fact the sound characteristic of any mode can be transferred to any of our latter day keys (ie, starting on any note), by preserving the gap pattern. Semitone, tone, tone, tone, semitone, tone, tone is always Phyrigian, for example, whatever the first note. Tone, tone, tone, semitone, is Lydian. And the Greeks did all this while they were still inventing moussaka. Makes you think.