One of my 2019 goals is to learn Haskell, to do this I picked up Haskell School of Music which teaches Haskell by showing how it can be used to create music. Here is how to get started (on Mac), as I had to look round a bunch of places to get going.
brew install fluid-synth
alias synth='fluidsynth ~/Lib/FluidR3GM.sf2'
cabal update cabal install Euterpea cabal install HSoM
Now let's play something! Start your synth (perhaps with an alias like above
ghci and now type:
import Euterpea play $ c 4 qn
c 4 is the C note from 4th Octave.
qn is quarter note (this follows the American convention... I barely know the 'British' one but apparently the American one is more standard for algorithmic music). You can play notes simultaneously with the
:=: operator and in sequence with
play $ c 4 qn :+: e 4 qn :=: e 3 qn
It is possible to create chord in a simple way:
cEx = chord [c 4 qn, e 4 qn, g 4 qn] play cEx
And you can operate on them e.g. transposing or building melodies from lists. In just a little code you seem to be able to build very complex melodies.