In kindergarten and early primary school, children are taught scales as having steps and half-steps, or tones and semitones (T and S). This naming conveys that between one scale note and the next is always “one” something (tone or semitone, step or half step), indicating that these notes are consecutive in the scale despite their different size.
This is great for very young minds but doesn’t reflect how intervals are measured and described in general use.
The smallest unit of musical pitch (in Western culture) is 1 semitone. The semitone is a basic unit, like a millimetre. (Smaller units exist but they measure expression such as vibrato or micro-tuning rather than musical notes). Larger intervals are measured in semitones, not tones and semitones. We say an octave is 12 semitones, not 6 tones or 5 tones and 2 semitones.
(Personally I find that calling 2 semitones a tone is confusing, given that a “tone” is also the American name for a note as well as a word for timbre.)
I never refer to “tones” as an interval size in any of my writing. For scales, I write 2 or 1 (semitones) instead of T or S.
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Can you explain how or why western music ended up having E to F and B to C as semitones, not whole tones as the notes suggest?
Hi James,
Thanks for your question.
I think it’s more the other way round.
Melodies in early Western culture were (and still are) made of selections of 7 notes within an octave. Starting on different notes gave the melodies different character.
Later we discovered that this happened because the notes weren’t all the same distance apart. In fact, there are 12 semitones within an octave. 7 doesn’t go into 12 so a 7-note scale can’t have every note 2 semitones apart.
It’s the irregular pattern of 2 and 1 semitone intervals between consecutive scale notes that give each mode (such as major or minor) its unique character.
A scale of whole tones (2-semitone intervals) is quite unnatural-sounding. It would never have been an option. It’s not musical to the Western ear because it doesn’t have a note a perfect 5th (7 semitones) above the root note. Scales without a perfect 5th can’t function in conventional music because the perfect 5th is needed to reinforce the root note so that we can feel it in the music.
I have explained some of this in my lesson post on modes, lesson 15, and also a little in lessons 8 and 10
https://musictheoryde-mystified.com/15-modes/
https://musictheoryde-mystified.com/8-what-is-a-scale/
https://musictheoryde-mystified.com/10-how-to-find-the-notes-of-a-scale/
As to why the 1-semitone intervals are B-C and E-F, just a consequence of which sound they decided to call A. Maybe the aeolian mode (the mode on A) was the most common when note names were first developed… in early history it was certainly much more popular in the Church, where most higher education took place, than the Ionian (major) mode.