Scales

A scale is an ordered ladder of notes spanning an octave, built from a tonic (its "home" note) and a fixed pattern of whole and half steps. The major scale is W-W-H-W-W-W-H; change the pattern and you change the flavour. Pick a tonic and a type below, then press Play to hear it climb and descend - the way you'd actually practise it.

Notice the spelling: each rung takes the next letter of the alphabet, so D major is D-E-F♯-G-A-B-C♯ - never G♭. That "one letter per step" rule is what makes a scale's spelling definite, and it's the foundation of key signatures.

The seven modes

Play only the white keys but start on a different note each time and you get the seven modes. Starting on C is Ionian - the plain major scale. Starting on A is Aeolian - the natural minor. The five in between (Dorian, Phrygian, Lydian, Mixolydian, Locrian) are the same seven notes heard from a different home, each with its own character. They're not new notes, just a new centre of gravity.

The minor that changes direction

Minor scales come in three forms. Natural minor (Aeolian) is the plain one. Harmonic minor raises the 7th to give a strong pull back home (the leading tone). Melodic minor is the odd one out: it raises the 6th and 7th going up, then reverts to natural minor coming down - so it literally sounds different ascending and descending. Pick it above and play both ways to hear the switch.

What a scale really is

A scale is a chosen handful of the twelve notes, put in order and treated as a ladder you climb and descend. What defines it is the pattern of steps between the rungs, written as whole steps (W) and half steps (H). The major scale's pattern is W-W-H-W-W-W-H, and that one shape, started on any of the twelve notes, gives the major scale in every key. Change the pattern and you change the character completely.

Major versus minor

The quickest way to feel the difference is the third degree. A major scale's third sits a major third above the tonic and tends to sound bright; a minor scale lowers that third a half-step and tends to sound darker. Both are diatonic, seven notes spread evenly across the octave, and a natural minor scale is in fact built from the very same notes as the major scale three steps below it, its relative major.

What's left for later

We've kept to scales where every degree takes its own letter. Pentatonic and blues scales skip letters and want their own treatment, so they're a concept still to come - as is naming a scale from notes you play, which is genuinely ambiguous (the same seven notes are several modes at once, depending on which you hear as home).