Scala is a freeware software application with versions supporting Windows, Mac OS X, and Linux. It allows users to create and archive musical scales, analyze and transform them with built-in theoretical tools, play them with an on-screen keyboard or from an external MIDI keyboard, and export them to hardware and software synthesizers.

Scala can retune MIDI streams and files using pitch bend. It also supports MIDI sysex and file-based tunings. Originally a command-line program, Scala now uses the Gtk+

GTK+

GTK+ is a cross-platform widget toolkit for creating graphical user interfaces. It is licensed under the terms of the GNU LGPL, allowing both free and proprietary software to use it. It is one of the most popular toolkits for the X Window System, along with Qt.The name GTK+ originates from GTK;...

 GUI toolkit. Scala is written in the Ada programming language, and is the work of Manuel Op de Coul of the Netherlands

Netherlands

The Netherlands is a constituent country of the Kingdom of the Netherlands, located mainly in North-West Europe and with several islands in the Caribbean. Mainland Netherlands borders the North Sea to the north and west, Belgium to the south, and Germany to the east, and shares maritime borders...

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Scala can also be used as a midi sequencer, by way of its ASCII

ASCII

The American Standard Code for Information Interchange is a character-encoding scheme based on the ordering of the English alphabet. ASCII codes represent text in computers, communications equipment, and other devices that use text...

-based sequencing format, seq. Because of its great flexibility when it comes to tuning formats, it is a very powerful tool for those who want to compose and sequence microtonal music

Microtonal music

Microtonal music is music using microtones—intervals of less than an equally spaced semitone. Microtonal music can also refer to music which uses intervals not found in the Western system of 12 equal intervals to the octave.-Terminology:...

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Scala's motto is "Invenit et perficit", Latin for "It finds and perfects" or "It discovers and accomplishes" in Latin

Latin

Latin is an Italic language originally spoken in Latium and Ancient Rome. It, along with most European languages, is a descendant of the ancient Proto-Indo-European language. Although it is considered a dead language, a number of scholars and members of the Christian clergy speak it fluently, and...

. Its logo is a Renaissance

Renaissance

The Renaissance was a cultural movement that spanned roughly the 14th to the 17th century, beginning in Italy in the Late Middle Ages and later spreading to the rest of Europe. The term is also used more loosely to refer to the historical era, but since the changes of the Renaissance were not...

-style relief print

Relief print

A relief print is an image created by a printmaking process where protruding surface faces of the matrix are inked; recessed areas are ink free. Printing the image is therefore a relatively simple matter of inking the face of the matrix and bringing it in firm contact with the paper...

 of a cherub

Cherub

A cherub is a type of spiritual being mentioned in the Hebrew Bible and cited later on in the Christian biblical canons, usually associated with the presence of God...

 holding a compass

Compass (drafting)

A compass or pair of compasses is a technical drawing instrument that can be used for inscribing circles or arcs. As dividers, they can also be used as a tool to measure distances, in particular on maps...

 and a globe inscribed with a diatonic musical scale and a circle of fourths

Circle of fifths

In music theory, the circle of fifths shows the relationships among the 12 tones of the chromatic scale, their corresponding key signatures, and the associated major and minor keys...

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File formats

Scala can open, transform, and save standard MIDI files. It can also export MIDI tuning tables in .tun format. It provides a native, human-readable sequencing language (.seq). But it is best known for its use of human-readable text files to store musical scales.

The Scala scale file format has become a standard for representing microtonal scales in a way that can be used by other software. The Scala site lists over thirty applications that support the format, including several major commercial packages like Apple Logic 7, Celemony Melodyne 3, and Cakewalk

Cakewalk (company)

Cakewalk, Inc. is a company based in Boston, Massachusetts that develops and sells music production software. The company's best known product is their comprehensive music sequencer named SONAR, which is designed for professional use. SONAR incorporates multi-track recording and editing of both...

Rapture and Z3TA+. Scala's developer also makes freely available an archive of over 3,500 Scala scale files, containing many musical scales of historical, cultural, and theoretical interest.