Arpeggigon === The arpeggigon is a music instrument inspired by Mark Burton's [reacTogon][]. It is written in Haskell using the FRP library [Yampa](http://hackage.haskell.org/package/Yampa-0.10.4) for the music generation, [Gtk2Hs](https://hackage.haskell.org/package/gtk-0.14.5) for the Graphical User Interface (GUI) and [jack](http://hackage.haskell.org/package/jack-0.7.1) for handling MIDI I/O. The code to interface with the exterior world is structured using reactive values and relations (see [this paper](http://www.cs.nott.ac.uk/~psxip1/papers/2015-HaskellSymposium-Perez-Nilsson-BridingGUIGapReactiveValues.pdf) and the libraries [here](https://hackage.haskell.org/package/keera-hails-reactivevalues-0.2.2.0) and [here](https://hackage.haskell.org/package/keera-hails-reactive-gtk-0.3)). Install guide --- The arpeggigon needs the [GTK+ 2.0 C API](http://www.gtk.org/) and the [JACK C API](http://jackaudio.org/) to be built. It is known to work with GHC 7.10.3 and GHC 8.0.1. Running the arpeggigon is then possible with: cabal sandbox init cabal install --only-dependencies cabal run arpeggigon To install the arpeggigon globally, one can call: cabal install This will create an executable located in `/.cabal-sandbox/bin/` from where it is possible to create a symbolic link to an object in the `PATH`. ln -s /.cabal-sandbox/bin/arpeggigon /arpeggigon Description --- ### The reacTogon The [reacTogon][] is a musical instrument invented based upon the [harmonic table](https://en.wikipedia.org/wiki/Harmonic_table_note_layout), a way of arranging notes where the various directions correspond to meaningful musical intervals. From that layout, the reacTogon defines an automaton: tokens of different kinds interact with *play heads* moving around on the board, altering their directions and eventually playing a note. The arpeggigon is an extended reacTogon. It is for instance possible to have multiple layers with different characteristics running in parallel, or to modify the way individual notes should be played, etc. ### Music generation The arpeggigon doesn't directly produce music, but is a [MIDI](https://en.wikipedia.org/wiki/MIDI) [JACK](http://jackaudio.org/) client. It then requires a JACK server to run when it is launched and to be connected to a MIDI synthetizer to produce music. ### Tokens There are five kinds of tokens currently supported, that appear in the following order in the arpeggigon's GUI: * ricochet token: plays a note and reorients the play head toward the direction it's pointing to, * start token: like the ricochet token but generated an impulsion when the machine starts, * stop token: plays a note and makes the play head disappear, * absorb token: like the stop token but doesn't play any note, * split token: splits the impulsion into five. ### Multiple layers It is possible to have multiple layers running in parallel, each one having it's own control settings. Adjustable parameters include: * the layer beat, * the strength at which notes should be played, * the volume, * the instrument, * the beats per bar for the given layer, * the possibility to make the layer restart automatically after a certain number of bars, specifying if the layer should completly restart or not. ### Note attributes Each tile, whether it's inhabited by a token or note is attributed a repeat counter, telling how long a play head should stay on it. For tiles inhabited by a token giving the possibility of a note being played, it is possible to adjust some parameters, including: * the note duration, * an articulation, allowing the note to be played stronger depending on its position in the bar, **Warning:** *Though it appears a slide can be specified, it is for now a missing feature.* ### Button semantics The start/restart button has a particular semantic. Pressing the start button makes the machine start and turns the button into a restart button. When pressed it will restart all the layers but take into account the layer restart policy to know if it should completely restart the layer or simply add the start heads to the already running ones. The stop button simply stops all the layers. ### Missing features This lists the buttons that have no effect but are yet present at the moment in the GUI. This features are being worked on in priority. * Recording a performance is not yet possible. * Configuration saving and loading is unavailable. * Slides are not implemented. * Tabs are not really named. ### Future features This lists the features that would be nice to add to the arpeggigon at some point: * a nicer GUI, with the possibility to display note names on the board, and see which note is being focused on. * a new “random split token”, that would redirect a play head in a random direction, or more generally split it in a random way. * an ALSA backend for Linux. [reacTogon]:https://www.youtube.com/watch?v=AklKy2NDpqs Copyright and license --- Copyright 2016, Guerric Chupin and Henrik Nilsson. The arpeggigon is licensed under the BSD 3-Clause License. A copy of the license is included in the [LICENSE](LICENSE) file.