\subsubsection{Intervals}
\seclabel{intervals}
% \url{http://en.wikipedia.org/wiki/Interval_(music)}
In music theory, an interval is the difference
(a ratio or logarithmic measure) in pitch between two notes
and often refers to those two notes themselves (otherwise known as a dyad).
Here we list some common names for some possible intervals.
\begin{haskelllisting}
> module Haskore.Basic.Interval where
> unison, minorSecond, majorSecond, minorThird, majorThird,
> fourth, fifth, minorSixth, majorSixth, minorSeventh, majorSeventh,
> octave, octaveMinorSecond, octaveMajorSecond, octaveMinorThird,
> octaveMajorThird, octaveFourth, octaveFifth, octaveMinorSixth,
> octaveMajorSixth, octaveMinorSeventh, octaveMajorSeventh :: Integral a => a
> unison = 0
> minorSecond = 1
> majorSecond = 2
> minorThird = 3
> majorThird = 4
> fourth = 5
> fifth = 7
> minorSixth = 8
> majorSixth = 9
> minorSeventh = 10
> majorSeventh = 11
> octave = 12
> octaveMinorSecond = octave + minorSecond
> octaveMajorSecond = octave + majorSecond
> octaveMinorThird = octave + minorThird
> octaveMajorThird = octave + majorThird
> octaveFourth = octave + fourth
> octaveFifth = octave + fifth
> octaveMinorSixth = octave + minorSixth
> octaveMajorSixth = octave + majorSixth
> octaveMinorSeventh = octave + minorSeventh
> octaveMajorSeventh = octave + majorSeventh
\end{haskelllisting}