klasma

Klasma is a chiptune music composition toolkit. It reads text files written in a purpose-designed DSL, and produces audio data, which can then be played or written to a WAV file.

prerequisites

Just Java (>= 1.6?) and make. Simply clone the repository and make; this should produce a klasma.jar, which contains everything.

use

For now, klasma is a command-line program only.

$ java -jar klasma.jar --help
usage: klasma [-i INPUT-FILE] (-o OUTPUT-FILE|--stdout|--play)
options:
  -i INPUT-FILE:    Specify a file to use as input.
                    Default: read from standard input.

  -o OUTPUT-FILE:   Specify a the name of a WAV file to write.

  --stdout:         Write WAV data to standard output.

  --play:           Play the track.

compose

notes

The most basic object in klasma is a note. Notes are written in a syntax based on scientific pitch notation; a note name, followed by an optional octave, followed by an optional length. For example:

C     -- A note omitting the octave and length.
C4    -- A note including the octave, but not the length.
D#3++ -- A note including both an octave and a length.

The note name can be anything from the list C, C#, Db, D, D#, and so on, or ^ to signify a rest.

The octave is an integer, representing the octave number. Klasma uses standard concert pitch, so A4 is 440Hz.

The length is a (possibly zero-length) series of + or -, followed optionally by a .. Each + doubles the length of the note, and each - halves it. A . multiplies the length by 1.5, just like a dotted note in sheet music. The default length is a crotchet (quarter-note). For example:

• C is a crotchet.
• C+ is a minim.
• C++ is a semibreve.
• C-- is a semiquaver.
• C--. is a dotted semiquaver.

blocks

A block is simply a name attached to a list of notes. Blocks are defined like so:

<blockName> : BLOCK
    <note> [<note>...]

For example:

cMajorScale : BLOCK
    C+
    D E F G A B
    C5+
    B A G F E D
    C+

rest : BLOCK
    ^++

Klasma is sensitive to whitespace; every line of notes must be indented so that it's clear which block they belong to.

waveforms

Klasma provides you with four waveforms: SQUARE, TRIANGLE, SAWTOOTH, NOISE. These control how a note is turned into audio data, and they affect the timbre of the note.

channels

A channel consists of a channel name, a waveform name, and a list of blocks.

<channelName> : CHANNEL <waveform>
    <block> [<block> ...]

For example:

cMajorScaleThreeTimes : CHANNEL SQUARE
    cMajorScale rest cMajorScale rest cMajorScale

This will play a C major scale three times, with rests in between, with a square wave.

tracks

A track is what you get from processing a whole file, which will consist of a number of block and channel declarations. When you ask klasma to compile a track, it will produce audio data by starting all the declared channels at the same time, and playing them concurrently.

There are some example tracks in the examples/ directory; see examples/example1.txt to get you started. Enjoy!