Whole-tone
Whole steps only: C D E F# G# A#. There are only two distinct whole-tone scales (on C and on C#). It has no leading tone and no perfect fifth: no hierarchy, a suspended and dreamlike sound. Derived chords: C+ (C E G#), C7#5, C9#5. It is used over augmented dominants (G7#5 → C) and for “dream” or “magic” effects.
Diminished (octatonic)
Alternates half step and whole step (or vice versa), eight notes, only three distinct transpositions.
- Half-whole on G: G Ab Bb B C# D E F. Over G7 it gives b9, #9, #11 and 13: it is the “elegant” altered-dominant scale.
- Whole-half on B: B C# D E F G Ab Bb. It is used over B°7, which in C functions as the dominant of C.
Every diminished seventh chord and every triad a minor third apart (G, Bb, Db, E) lie within the same octatonic scale.
Applications
- Jazz: G7(b9,13) → Cmaj7 with a melody from the half-whole scale.
- Film and video games: diminished patterns for suspense.
- Dark metal, drill and trap: octatonic fragments (A Bb C Db) for aggressive melodies over an 808 in A.
Real example
“Voiles” by Debussy (Préludes, Book I, 1910) is built almost entirely on the whole-tone scale, with a brief pentatonic section: the textbook example of how the absence of tonal hierarchy creates suspension.