Talk:Interval (music)

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Interval number and quality[edit]

Being a little rusty on interval naming, I recently turned to this article. I am afraid to say I found it really quite difficult to understand, and on a practical level, not particularly helpful. I am not sure how I would have fared had I been coming to the topic for the first time. I've had a go at preparing a new version, but with regard to the extensive discussions on these talk pages I thought I should post a draft here for comment:


I did not include the following material, because I think this section should be a concise description of interval naming. Many visitors probably come looking for that. (For this reason I have also renamed the section "Interval naming".) I would not intend to exclude this material altogether, but maybe it could be moved into different sections if it is not there already:

Perfect intervals are so-called because they were traditionally considered perfectly consonant,[1] although in Western classical music the perfect fourth was sometimes regarded as a less than perfect consonance, when its function was contrapuntal. Conversely, minor, major, augmented or diminished intervals are typically considered to be less consonant, and were traditionally classified as mediocre consonances, imperfect consonances, or dissonances.[1]
By definition, the inversion of a perfect interval is also perfect. Since the inversion does not change the pitch of the two notes, it hardly affects their level of consonance (matching of their harmonics). Conversely, other kinds of intervals have the opposite quality with respect to their inversion. The inversion of a major interval is a minor interval, the inversion of an augmented interval is a diminished interval.
Interval numbers do not represent exactly interval widths. For instance, the interval C–D is a second, but D is only one staff position, or diatonic-scale degree, above C. Similarly, C–E is a third, but E is only two staff positions above C, and so on. As a consequence, joining two intervals always yields an interval number one less than their sum. For instance, the intervals C–E and E–G are thirds, but joined together they form a fifth (C–G), not a sixth. Similarly, a stack of three thirds, such as C–E, E–G, and G–B, is a seventh (C–B), not a ninth.

I have also tried to tidy the diagrams up a little: I feel there is a danger of the sheer number and complexity of the diagrams being confusing, although the information in them is undoubtedly useful. I've added the interval names to the various diagrams for perfect, major/minor and augmented/diminished intervals (I think there is currently a bug in the caching system which means the original files/thumbnails might still show, but the correct files *have* been uploaded) and removed the diagram of "main intervals", as that is now redundant.

Looking forward to any feedback. Gnathan87 (talk) 02:18, 30 January 2013 (UTC)

On reflection, I have edited this section to also include the "shorthand notation" section currently in the article. Gnathan87 (talk) 04:28, 30 January 2013 (UTC)
A minor quibble with this clause, quoted above: Since the inversion does not change the pitch of the two notes...: usually inverting an interval is defined as moving one of the notes up or down an octave, which does change its pitch, although not its note name or pitch class. —Wahoofive (talk) 16:41, 30 January 2013 (UTC)
In your linked draft, it's not correct to say that an interval is named relative to a major scale built on the lower note. For example, a minor third is still a minor third, no matter its location in a major scale (such as between the third and fifth scale degrees), and if you try to say that it's named relative to a major scale on the bottom note, a minor third wouldn't even occur there, which gets you in trouble. Once you started explaining things that way, you had to pull in unnecessary key changes and unnecessary accidentals, just to come back to the same interval you started with. For example, you gave the interval of Eb to A (which would naturally occur between the fourth and seventh scale degrees in Bb major), and then you tried to explain it as occurring relative to Eb Major, which it doesn't naturally occur in, so you added an accidental in front of the A to make it A natural (even though it was already A natural when you started), to counter the unnecessary key change that you inserted that would have made it Ab. See what I mean? The naming process is simpler than that. We know Eb to A has to be some kind of fourth because it encompasses four note-name letters (E, F, G, and A, acknowledging that note names wrap around) a.k.a. four staff positions, and we know it has to be an augmented fourth because it's a semitone wider than a perfect fourth. Notice we didn't need to know the key to determine that. (talk) 23:05, 2 May 2015 (UTC)

Alternative names for perfect unison, minor second, augmented unison[edit]

In the following section, we are discussing about the meaning of the terms tone and ditone. Some contributor, however, opened a secondary discussion about the footnotes appearing in the main table which provide widely used alternative names for P1, m2, and A1. I created this section to discuss this secondary topic separately, to avoid confusion. The alternative names for P1, m2, and A1 are:

  • Perfect prime (P1)
  • Diatonic semitone (m2)
  • Chromatic semitone or augmented prime (A1)

See separate section above about the usage in music theory textbooks of the terms perfect unison/prime and augmented unison/prime. See Semitone for details about diatonic and chromatic semitones.
We can either specify all these alternative names, or omit them all. There's no reason to delete only one of the relevant footnotes. Personally, I was glad to discover in the table an alternative name for unison, which I totally ignored and which is apparently used by several authors (see separate section above).
Please consider that the choice to specify, in the main table, widely used alternative names for some intervals is a personal preference. We need consensus before taking a final decision. It would be nice to know the opinion of many editors about this topic. Paolo.dL (talk) 09:47, 26 August 2013 (UTC)

So it is "unbelievable (that) you insist" that a perfect prime cannot be mentioned as alternate name for a perfect unison. −Woodstone (talk) 09:50, 26 August 2013 (UTC)
The real sad thing is that there is no good neutral term for the octave, which is so biased towards the traditional diatonic scale. A pity that was not called a ditone. −Woodstone (talk) 10:00, 26 August 2013 (UTC)
As I explained in my edit note (17:33, 25 August 2013), your edit not only duplicates an existing footnote, and information already provided in the previous text, but also implies that both P1 and d2 are called perfect prime, which is false. And this is the second time you do this kind of mistake. On 09:36, 24 August 2013‎ I reverted a previous very similar edit of yours with the following edit note: "[...]. Also, the Diminished second is not called a unison!". Notice the exclamation mark. Paolo.dL (talk) 10:30, 26 August 2013 (UTC)
I am not making a mistake. You still don't understand. The key column in the table is the number of semitones. The other columns give names for that size. First as perfect/minor/major, then as diminished/augmented and finally some alternates. Since a perfect prime is 0 semitones, it fits very well in that line. Clearly this is all meant in an enharmonic sense, with an abstract size of semitone (or when using everything in 12ET). −Woodstone (talk) 16:26, 26 August 2013 (UTC)
Absurd. There's a separate column for perfect intervals. By the way, as I wrote in my edit note, both a footnote and the previous text already provide the alternative name for perfect octave. Paolo.dL (talk) 11:06, 27 August 2013 (UTC)
The purpose of a table is to present all information in a systematic way. Hiding information in footnotes is not compatible with that. Do you contest that "0 semitones" = "perfect unison" = "perfect prime"? If not, why is one not an alternate name for the others? I really don't see your point. −Woodstone (talk) 13:12, 27 August 2013 (UTC)

There is a column dedicated to perfect, minor, and major intervals, as specified in its column label. The only option you have, if you want to show the alternative name and you don't like footnotes, is to write "perfect octave or perfect prime" in the first cell of that column (isn't this obvious?). However, I do not agree about this option because:

  1. IMO this table should only show the most commonly used names for the main intervals
  2. Semitone, tone and tritone, for most people, are not synonyms of m2, M2, A4, so it does not matter whether they are more or less commonly used than m2, M2, A4. They are widely used names within a different and widely used naming convention, which is not based on interval quality and diatonic number.
  3. "Perfect octave" is used in textbooks twice as frequently as "perfect prime" (about this terminological preference, Justlettersandnumbers inserted a reference in the article, and I provided references in a separate section above).
  4. The alternative name "perfect prime" is specified right above the table, within the same section of the article (Main intervals).
  5. Full information about alternative names (including "perfect prime") is given later in a separate table with a different structure, within a separate section called Alternative interval naming conventions.

Based on this, we might even reach consensus here about deleting all the footnotes about alternative names (not only that about perfect prime). It would not be a tragedy. I would like to know the opinion of others about this. As I wrote, I will abide to consensus.
Paolo.dL (talk) 15:13, 27 August 2013 (UTC)

It would be OK to make a special notes subsection for the naming table (right after the table, not at the end of the article), to avoid repeating info. You might want to consider a more parallel system of tables if one is for one set of naming conventions and one is for another. Or just put all the names into one table. Dicklyon (talk) 15:31, 27 August 2013 (UTC)

Thank you, Dicklyon. In my opinion, Main intervals should be just an overview, and should be kept as simple as possible. The separate section called Alternative interval naming conventions is too complex to be used as a subsection of Main intervals. As a consequence, I believe that the only viable options are:

  • Option 1 (Visible information): we write the alternative names for P1, m2, A1 in the table rather than in the footnotes.
  • Option 2 (Hidden information): we keep the footnotes
  • Option 3 (No information): we delete the footnotes

Remember that we also provide information about "perfect prime" in the text above the table, and a much more detailed analysis in a separate section at the end of the article (Alternative interval naming conventions). Some redundancy in this separate section is necessary and welcome. To avoid redundancy, we would need to delete both the footnotes and the column about "Widely used alternative names", in Main intervals. But this is just my opinion. Let me know if you agree.
Paolo.dL (talk) 16:23, 27 August 2013 (UTC)

Rearranging the main table[edit]

PMFJI, but I have an idea for simplifying the main table which I hope won't be too controversial. Although the Tritone is not a perfect, major or minor interval, it is a very legitimate diatonic interval (representing B–F or F–B). I suggest moving the Tritone to column 2 and renaming the column "Diatonic intervals" to incorporate the addition as follows (you may have to fix the table a little):

Number of
Diatonic intervals Short Augmented or
Short Widely used
alternative names
Short Audio
0 Perfect unison[2][3] P1 Diminished second d2 About this sound Play 
1 Minor second m2 Augmented unison[2][3] A1 Semitone,[4] half tone, half step S About this sound Play 
2 Major second M2 Diminished third d3 Tone, whole tone, whole step T About this sound Play 
3 Minor third m3 Augmented second A2 About this sound Play 
4 Major third M3 Diminished fourth d4 About this sound Play 
5 Perfect fourth P4 Augmented third A3 About this sound Play 
6 Tritone[5] TT Diminished fifth d5 About this sound Play 
Augmented fourth A4
7 Perfect fifth P5 Diminished sixth d6 About this sound Play 
8 Minor sixth m6 Augmented fifth A5 About this sound Play 
9 Major sixth M6 Diminished seventh d7 About this sound Play 
10 Minor seventh m7 Augmented sixth A6 About this sound Play 
11 Major seventh M7 Diminished octave d8 About this sound Play 
12 Perfect octave P8 Augmented seventh A7 About this sound Play 

-- Glenn L (talk) 18:26, 27 August 2013 (UTC)

I thank you for joining the discussion but I disagree for three different reasons: (1) The column "Widely used alternative names" should contain (as it currently does) all the most common terms based on the concept of "tone", i.e. semitone, tone, tritone. (2) Both d5 and A4 may be defined "diatonic intervals", meaning that they appear in a diatonic scale. (3) The expression "diatonic intervals" is so ambiguous that actually means nothing. See Diatonic and chromatic.
So, honestly I can't see a simplification in your proposal, but a complication which scrambles a well designed table, in which each column is unambiguosly defined. In other words, if it ain't broken, don't fix it. Sorry, I don't want to be impolite, I just want to be honest.
What about the options we are discussing in the previous section? What do you prefer? Please answer above. According to WP:Refactoring talk pages, I created a separate section for discussing your proposal, which has got nothing to do with the topic discussed in the previous section ("Alternative names for perfect unison, minor second, augmented unison").
Paolo.dL (talk) 19:58, 28 August 2013 (UTC)

Contradiction between illustration and its MIDI -- Main_intervals_from_C.png and Intervals.mid[edit]

The Main_intervals_from_C.png file illustrates both C and F♯ (to show an augmented fourth) and C and G♭ (to show a diminished fifth). In Western intonation, or whatever it's called, these two dyads sound exactly the same; they are essentially one. The MIDI does not play it twice. Consequently, there is one less dyad played in the MIDI than shown on the illustration. Now, I figured this out right away and understood it, but I wouldn't hold everybody to my standard of music-theory knowledge. I would, in fact, expect a number of people to get confused, even frustrated.

Is this worth changing? It would not be hard for me to edit my copy of the MIDI and figure out how to upload it (though it would be my first time messing with anything besides text), but I don't feel like I should do it without some consensus. (And I would rather not do it myself, because I don't really understand the licensing bit.) More relevantly, I see that another article, Dyad (music) uses the same MIDI, and perhaps fixing this problem here would create a problem there(?)

Ben Culture (talk) 13:18, 28 August 2014 (UTC)

Remark and request[edit]

I thought this was a great article, really interesting topic and really well written, thank you. I did find one sentence that I underlined that I thought was unclear and could do with review ˜```25 June 2017 Australian Eastern Standard time. Mgdyason (talk) 11:46, 25 June 2017 (UTC)

Sentence was clarified. −Woodstone (talk) 16:05, 26 June 2017 (UTC)

P.S. The following footnotes you see below apply to the previous topic. System glitch? ←Ben Culture (talk) 14:17, 28 August 2014 (UTC)

Nonsense sentence?[edit]

What on Earth does this mean? "These names describe not only the difference in semitones between the upper and lower notes, but also how the interval is spelled."

For a start the names of intervals don't refer to the number of semitones. And does "spelled" have some kind of technical meaning in this context? If so shouldn't that be explained? (talk) 22:32, 1 July 2017 (UTC)

Yes, an "augmented fourth" and a "diminished fifth" are different enharmonic spellings of the same interval (a tritone, or six semitones). I have added a wikilink to the word "spelling" in the article and re-worded the sentence. I hope this clarifies. Burninthruthesky (talk) 02:28, 2 July 2017 (UTC)
    • ^ a b Definition of Perfect consonance in Godfrey Weber's General music teacher, by Godfrey Weber, 1841.
    • ^ a b The perfect and the augmented unison are also known as perfect and augmented prime.
    • ^ a b Cite error: The named reference prime was invoked but never defined (see the help page).
    • ^ The minor second (m2) is sometimes called diatonic semitone, while the augmented unison (A1) is sometimes called chromatic semitone.
    • ^ Cite error: The named reference TritoneA4 was invoked but never defined (see the help page).