I heard about the tonus peregrinus or ninth tone. The corresponding article in German Wikipedia claims that Deep Purple's Child in Time is essentially composed in this key:

Tonus peregrinus is also commonly used in rock music. Deep Purple's Child in Time, for instance, is composed of four-bar measures (?) dominated by chords a minor, a minor, g major and again a minor" [translation mine, to be taken with a pinch of salt]

(original) Auch in der Rockmusik wird die Modalität des Tonus peregrinus gerne verwendet. Das Stück Child in Time von Deep Purple ist zum Beispiel viertaktig gegliedert und die vier Takte werden von den Akkorden a-Moll, a-Moll, G-Dur und erneut a-Moll dominiert.

Can anyone confirm that and perhaps point me to further examples of popular songs that make use of this tone?

  • 1
    Please, don't close this question. I've never heard before of this concept of tonus pregrinus and I want to learn more. Certainly the analisys of specific examples is useful, if not required, to properly understand a harmony concept. The question can be perhaps improved to not make it a "look for key" one: WHY is Deep Purple's Child in TIme said to be in this Tonus Peregrinus? – José David Aug 18 '16 at 10:29

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