Schoenberg

Schoenberg

Paradigm(s)	imperative
Designed by	User:Tomer
Appeared in	2025
Memory system	Cell-based
Dimensions	one-dimensional
Computational class	Turing complete
Major implementations	Original
Influenced by	Piet, brainfuck
File extension(s)	.mid

Schoenberg is an esoteric programming language where programs are written as MIDI files. A MIDI file is basically digital sheet music that tells a computer which notes to play when and how loudly.

The programming language interpreter, and transpilers between Schoenberg and brainfuck programs, can be found on GitHub.

Semantics

The operational semantics of a Schoenberg program directly match those of a brainfuck program. Since brainfuck is Turing complete, so is Schoenberg.

Like brainfuck, Schoenberg operates on an array of memory cells, each initialized to zero. There is a pointer, initially pointing to the first memory cell, and there are commands for moving the pointer, modifying the current cell, outputting the current cell, and looping.

Syntax

Since Schoenberg programs are MIDI files, its syntax is not text-based.

Instead, commands are controlled by pitch class distance, velocity, and overlap. Rhythm has no effect on a program's behavior unless it causes notes to overlap.

Command	Description	Syntax	amount	Brainfuck
Decrement	Decrement the pointer cell by amount	Play a note 1 pitch class away from the current note	$\left\lceil {\frac {{\text{vel}}+1}{32}}\right\rceil$	-
Increment	Increment the pointer cell by amount	Play a note 2 pitch classes away from the current note	$\left\lceil {\frac {{\text{vel}}+1}{32}}\right\rceil$	+
Move left	Move the pointer left amount times	Play a note 3 pitch classes away from the current note	$\left\lceil {\frac {{\text{vel}}+1}{64}}\right\rceil$	<
Move right	Move the pointer right amount times	Play a note 4 pitch classes away from the current note	$\left\lceil {\frac {{\text{vel}}+1}{64}}\right\rceil$	>
Output	Output the pointer cell	Play a note 5 pitch classes away from the current note	N/A	.
Input	Input a byte into the pointer cell	Play a note 6 pitch classes away from the current note	N/A	,
Loop start	Jump past the matching loop end if the pointer cell is 0	Play a note that overlaps the current note (a "loop note")	N/A	[
Loop end	Jump back to the matching loop start if the pointer cell is not 0	Stop playing an active loop note	N/A	]

Additionally:

• Playing the same note twice in a row, corresponding to a pitch class distance of 0, is a no-op. However, playing and overlapping two different notes with the same pitch class (e.g. in different octaves) can be used to start loops without adding other commands.
• When playing multiple notes at exactly the same time (e.g. a chord), the chronology of the notes is considered to be the ascending pitch order.

Every MIDI file is a syntactically valid Schoenberg program, although most don't do anything useful.

Examples

Some of these were written by hand while others were transpiled from brainfuck programs.

MIDI	Description	Audio (synthesized using TiMidity)	Source
hello_world.mid	Prints Hello, World!	hello_world.mp3	Esolang Wiki
cell_width.mid	Prints the interpreter's cell width	cell_width.mp3	Esolang Wiki
echo.mid	Prints the input, like echo	echo.mp3	User:Tomer
wc.mid	Counts input lines, words, and bytes, like wc	wc.mp3	Daniel B. Cristofani
fib.mid	Prints the entire Fibonacci sequence	fib.mp3	Daniel B. Cristofani
bubble_sort.mid	Sorts the input bytes using bubble sort	bubble_sort.mp3	Daniel B. Cristofani
insertion_sort.mid	Sorts the input bytes using insertion sort	insertion_sort.mp3	Daniel B. Cristofani
quick_sort.mid	Sorts the input bytes using quick sort	quick_sort.mp3	Daniel B. Cristofani
brainfuck_interpreter.mid	Runs a brainfuck program on its input, which should be separated by an exclamation point	brainfuck_interpreter.mp3	Daniel B. Cristofani

All the programs can be found on GitHub.

Etymology

The programming language is named after Arnold Schoenberg (1874–1951), who is widely considered to be the father of atonal music.

Writing tonal music, the basis of Western music composition, requires limiting yourself to the pitch classes of a chosen key, but this is incredibly hard to do when writing Schoenberg programs.

For example, if you want to decrement the pointer cell, then the next note must be 1 pitch class away. This leaves you with only two options for the next note's pitch class, but it's possible neither of those pitch classes is in the chosen key.

As a result, Schoenberg programs tend to be atonal.

External resources

• Tomer Aberbach's post about Schoenberg
• Original implementation