but I think I've just had an aha moment:
a half-step is a minor 2nd
a whole-step is Major 2nd
a scale is a specific series of intervals
the Diatonic Major Scale is
Major 2nd
Major 2nd
minor 2nd
Major 2nd
Major 2nd
Major 2nd
minor 2nd
the diatonic minor Scale is
Major 2nd
minor 2nd
Major 2nd
Major 2nd
minor 2nd
Major 2nd
Major 2nd
Whereas:
Pentatonic minor Scale is:
minor 3rd
Major 2nd
Major 2nd
minor 3rd
Major 2nd
etc with all the other different sets of intervals
and that technically there can be as many different types of scales as there can be different series of intervals between any octave series of notes
a Diatonic scale is a series of 7 intervals - across 8 notes - bridging an octave
a Pentatonic scale is a series of 5 intervals - across 6 notes - bridging an octave
The chromatic scale is a series of 12 minor 2nds...
and that once one understands this... then one no longer refers to half-steps and whole steps; but can think exclusively in terms minor 2nds; major 2nds; and all the other larger intervals such as Fifths?
by the way: why is it called a "perfect" Fifth?
