Why is it called a diatonic scale

chromatic

Examples:

The accordion is a chromatic hand-drawn instrument, built according to the chromatic scale with semitones. [Mittelbayerische, 21.10.2017]

For the middle part of the work, however, it [the note G] undergoes an alteration, a chromatic change to G sharp, which opens up completely new possibilities in terms of key, especially in the reinterpretation as A flat, from which it again […] for the final part G returns. [Neue Zürcher Zeitung, October 22, 2011]

Because even in the [Wagner] overture to “Faust”, a chromatic motif, descending in semitones, creeps into a light-hearted, cheerful music that points to the underworld of Mephistus [...]. [Rhein-Zeitung, January 17, 2019]

[The opera] "Moses und Aron" is based on a series established by Schönberg from the twelve chromatic semitones of a scale. In doing so, the composer created completely new worlds of sound and often increased the musical expression to a monumental level […]. [Berliner Zeitung, 26.03.2004]

The largo with dark pedal steps and a mysterious minor melody in the upper part often modulates through short chromatic series between the tones. [Saarbrücker Zeitung, 18.06.2001]

It may be a question of the kind that children ask, but why did no Baroque composer compose twelve tones? When everything was at hand: instruments that could be played chromatically, notation with all the necessary accidentals […]. [Die Zeit, 04/15/1999]

Depending on the number of strings, the tuning of the resonance and accompanying strings results in a diatonic to completely chromatic scale [Brockhaus-Riemann-Musiklexikon, Berlin: Directmedia Publ. 2000 [1989], p. 855], depending on the number of strings.

The tr. (= Tritone) is included in the diatonic scale (e.g. f – h in C major), but is interpreted as the chromatic alteration of an interval that is one semitone larger or smaller, i.e. H. as an excessive fourth or diminished fifth; in the narrower sense only means the excessive fourth tr. (= tritone) [.] [Brockhaus-Riemann-Musiklexikon, Berlin: Directmedia Publ. 2000 [1989], p. 10639]