Microtonality is An
interval in any
musical scale
smaller than a
semitone.
Additionaly, A semitone is an interval
equal to a half
tone in the standard
diatonic scale. Also called half step, half tone.
The use of microtonility is more used in Eastern countries, especially
India,
Saudi Arabia, and the like, because with
instruments such as the
sitar, it's easier to slide into
tones with
values deemed as "mircotonal".