# Why do people say "an octave louder"? **URL:** \ **Category:** Factual Questions\ **Created:** [January 10, 2016, 7:37pm UTC](https://boards.straightdope.com/t/why-do-people-say-an-octave-louder/742719 "2016-01-10T19:37:24Z")\ **Posts on this page:** 5\ **Page:** 3
**Author:** ![drad\_dog](https://avatars.discourse-cdn.com/v4/letter/d/aeb1de/32.png) [@drad\_dog](https://boards.straightdope.com/u/drad_dog)\ **Post date:** [January 13, 2016, 4:08am UTC](https://boards.straightdope.com/t/why-do-people-say-an-octave-louder/742719/41 "2016-01-13T04:08:55Z")
> [@pulykamell](#): > > What part of it doesn’t make sense? To be consistent, he’s right: it’s either 7 & 12 or 8 & 13 for both scales from octave to octave. However, for whatever reason, people tend to double count the octave in a diatonic scale for 8 notes (I guess to have “octave” make sense, although a major or minor scale is heptatonic, not octatonic), but not in the chromatic scale. Octave means you have reached the 8th degree of a scale which is identified as a repetition of the tonic. There is no tonic in a chromatic scale. > **[Chromatic scale](https://en.wikipedia.org/wiki/Chromatic_scale)** > > The chromatic scale (or twelve-tone scale) is a set of twelve pitches (more completely, pitch classes) used in tonal music, with notes separated by the interval of a semitone. Chromatic instruments, such as the piano, are made to produce the chromatic scale, while other instruments capable of continuously variable pitch, such as the trombone and violin, can also produce microtones, or notes between those available on a piano. > Most music uses subsets of the chromatic scale such as diatonic scales... The total chromatic (or aggregate[3]) is the set of all twelve pitch classes. ---
**Author:** ![pulykamell](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/pulykamell/32/3166_2.png) [@pulykamell](https://boards.straightdope.com/u/pulykamell)\ **Post date:** [January 13, 2016, 4:17am UTC](https://boards.straightdope.com/t/why-do-people-say-an-octave-louder/742719/42 "2016-01-13T04:17:46Z")
> [@drad\_dog](#): > > Octave means you have reached the 8th degree of a scale which is identified as a repetition of the tonic. > > There is no tonic in a chromatic scale. > > [Chromatic scale - Wikipedia](https://en.wikipedia.org/wiki/Chromatic_scale) > > The total chromatic (or aggregate[3]) is the set of all twelve pitch classes. Yes. I know that. ---
**Author:** ![pulykamell](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/pulykamell/32/3166_2.png) [@pulykamell](https://boards.straightdope.com/u/pulykamell)\ **Post date:** [January 13, 2016, 4:32am UTC](https://boards.straightdope.com/t/why-do-people-say-an-octave-louder/742719/43 "2016-01-13T04:32:55Z")
Basically, the point is just a nitpick. A diatonic scale has seven pitch classes . A chromatic has twelve. If you read the original post being responded to, **engineer\_comp\_geek** says the Western scale has 12, not 8, tones between octaves if you include the chromatics. There are 5 extra non-diatonic notes between octaves if you include the chromatics. So the statement should either have the numbers 12 and 7 or 13 and 8, depending on whether you want to count the octave. I would go with 12 and 7, and say that Western scales are generally divided in 7 sections, not 8. ---
**Author:** ![drad\_dog](https://avatars.discourse-cdn.com/v4/letter/d/aeb1de/32.png) [@drad\_dog](https://boards.straightdope.com/u/drad_dog)\ **Post date:** [January 13, 2016, 5:11am UTC](https://boards.straightdope.com/t/why-do-people-say-an-octave-louder/742719/44 "2016-01-13T05:11:12Z")
> [@pulykamell](#): > > Basically, the point is just a nitpick. A diatonic scale has seven pitch classes . A chromatic has twelve. If you read the original post being responded to, **engineer\_comp\_geek** says the Western scale has 12, not 8, tones between octaves if you include the chromatics. There are 5 extra non-diatonic notes between octaves if you include the chromatics. So the statement should either have the numbers 12 and 7 or 13 and 8, depending on whether you want to count the octave. I would go with 12 and 7, and say that Western scales are generally divided in 7 sections, not 8. For a nitpick you are really digging in. No tonic means it is meaningless to say there are 13 notes in the scale. There are only 12, and never 13. In a major scale the 8th note is the cycling of the **tonic** , thus called an **octave**. The eighth note may be called part of the scale because it is the tonic, in other words it has a musical value coming around again, where in the chromatic there is none. Think about it any way you want. ---
**Author:** ![pulykamell](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/pulykamell/32/3166_2.png) [@pulykamell](https://boards.straightdope.com/u/pulykamell)\ **Post date:** [January 13, 2016, 5:38am UTC](https://boards.straightdope.com/t/why-do-people-say-an-octave-louder/742719/45 "2016-01-13T05:38:47Z")
Either way works. [Previous page](https://boards.straightdope.com/t/why-do-people-say-an-octave-louder/742719.md?page=2)