A musical scale is an organised collection of pitches, often demonstrated in ascending or descending order. Its pattern of intervals offers a recognisable palette for melodies, basslines and harmony. Scales are useful starting points, not rules forbidding every other note.
This introductory reference explains the basic patterns and includes an interactive Scale Explorer, where you can change the starting pitch, compare scale types and hear the results.
What makes a scale?
A semitone is the interval between adjacent keys on a conventional equal-tempered piano. A whole tone spans two semitones. Scales combine these intervals in recognisable patterns that recur at different pitch levels.
For example, C major contains C–D–E–F–G–A–B, returning to C an octave higher. The semitone steps are between E and F and between B and C.
Major and natural minor scale patterns
The major-scale pattern is whole–whole–half–whole–whole–whole–half (W–W–H–W–W–W–H). In C major it gives C–D–E–F–G–A–B–C; starting on G, the same pattern gives G–A–B–C–D–E–F♯–G.
Natural minor uses W–H–W–W–H–W–W. A natural minor is A–B–C–D–E–F–G–A; C natural minor is C–D–E♭–F–G–A♭–B♭–C. The interval pattern, not a prescribed mood, defines the scale.
Explore scales on the interactive keyboard
Choose a root note and scale type below. The keyboard highlights the notes in that collection, and the controls let you play the scale up or down. Begin by comparing C major with C natural minor, then try a pentatonic scale, the blues scale or one of the modes.
The difference between a scale and a key
A scale identifies a pitch collection and its interval pattern. A key is a tonal framework: a particular note or chord is established as the tonic, a sense of musical home. Using the white keys alone does not automatically establish the key of C major.
C major and A natural minor use the same seven pitch classes but may establish different tonics. These are relative keys. C major and C minor are parallel keys: they share tonic C but have different pitch collections.
Pentatonic, blues and modal scales
Major pentatonic uses degrees 1, 2, 3, 5 and 6: C–D–E–G–A. Minor pentatonic uses 1, ♭3, 4, 5 and ♭7: A–C–D–E–G. A common six-note minor blues scale adds a flattened fifth: A–C–D–E♭–E–G.
Modes such as Dorian and Mixolydian have distinctive interval structures, but their identity also depends on which pitch is heard as tonic. For instance, D Dorian contains B natural, while D natural minor contains B♭. Hearing that difference over a sustained D is a useful comparison.
Using scales when composing
A scale can guide a riff or melody, provide pitches for basslines and support improvisation. In a MIDI Piano Roll the vertical positions show pitch, making interval patterns easy to recognise. But passing notes and chromatic notes outside a scale may be expressive choices, not mistakes. The musical context matters.
Continue exploring How Music Works
For more detail on scale degrees, relative and parallel keys, tonal centres and key signatures, see Scales and Keys Explained, Musical Modes and Pentatonic and Blues Scales. You can also explore Understanding Notes, Intervals and Modes in the Music Production Reference Library.