Scala scale file format

This page is intended for developers of music software who wish to support reading or writing of Scala scale (.scl) files. This file format for musical tunings is a standard for exchange of scales, owing to the size of the scale archive of over 4000 scales and the popularity of the Scala program. With the file's human readable format it's also useable for including scales in e-mail or discussion group postings.

The rules

So these lines are all valid pitch lines:
81/64
408.0
408.
5
-5.0
10/20
100.0 cents
 100.0 C#
 5/4   E\
Here is an example of a valid file:
! meanquar.scl
!
1/4-comma meantone scale. Pietro Aaron's temperament (1523)
 12
!
 76.04900
 193.15686
 310.26471
 5/4
 503.42157
 579.47057
 696.57843
 25/16
 889.73529
 1006.84314
 1082.89214
 2/1
A simple advise: put the filename on the first line behind an exclamation mark. Then someone receiving the file and reading it knows a name under which to save it.

To developers of MIDI software: you should be aware that there is another Scala file type for mapping key/note numbers to scale degrees, called a keyboard mapping, with file extension .kbm . In absence of support for keyboard mapping files, you may choose any mapping you want, but it will severely limit the musical usability, as argued in this article from SoundBytes. The description is here: Scala Keyboard Mappings.

1) The user can choose the character set that he/she requires, but if a file is intended to become included in the scale archive, it should be in ISO 8859-1 'Latin-1' or the ASCII subset.

Scale Archive

The scale archive can be freely downloaded. See the contents listing for a brief description of each scale file. The scales are at: http://www.huygens-fokker.org/docs/scales.zip.

Other software

Other programs which support the Scala scale format:

See also List of microtonal software plugins.

© Manuel Op de Coul, 2001-2025
coul@huygens-fokker.org

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