TurtlesTurtlesTurtles - A quick-start with Euterpea

Posted on November 29, 2018

A guide how to set up Euterpea and make some noise.

We assume that you’ve got Euterpea installed either via cabal or a package manager, such as portage, if not:

     $ cabal install euterpea

     $ emerge euterpea

Let’s see if it gets picked up by ghci:

     $ ghci
     GHCi, version 8.4.4: http://www.haskell.org/ghc/  :? for help
     Loaded GHCi configuration from /home/madjestic/.ghci
     Prelude Text.Show.Unicode> import Euterpea
     Prelude Text.Show.Unicode Euterpea>

Now we will use JACK to create a playback device for Euterpea to use to play musice:

start qjackctl
start qsynth
run the JACK server via qjackctl interface
run devices to see of Euterpea see the qsynth:

Prelude Text.Show.Unicode Euterpea> devices

Input devices: 
  InputDeviceID 1	Midi Through Port-0

Output devices: 
  OutputDeviceID 0	Midi Through Port-0
  OutputDeviceID 2	qjackctl
  OutputDeviceID 3	Synth input port (qsynth:0)

We can see here that qsynth is seen by Euterpea as a device number 3.

Let’s ask Euterpea about instruments that it can play:

Prelude Text.Show.Unicode Euterpea> :i InstrumentName
data Message = ... | InstrumentName !String | ...
   -- Defined in ‘Codec.Midi’

   data InstrumentName
   = AcousticGrandPiano
   | BrightAcousticPiano
   | ElectricGrandPiano
   | HonkyTonkPiano
   | RhodesPiano
   ...

Finally, let’s tell Euterpea to send a note to qsynth (device number 3) via JACK to play:

playDev 3 $ instrument Clavinet $ c 4 qn

If all went fine, you should hear a sound being played.

Happy hacking!