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as a programmer and a classically trained pianist, this section: > For example, the notes C, E and G (The C major chord) can have any of the following names, b

by mjg2 2y ago

as a programmer and a classically trained pianist, this section: > For example, the notes C, E and G (The C major chord) can have any of the following names, based on what is considered to be the root note. > root note chord name > C C Major > E E Minor #5 > G G sus4 (13) > (To the best of my knowledge, I'm no music theorist) is disqualifying for any usefulness in this program-- it will lead to more misguidance than clarity. without theory, there is no reason. i would analyze these inversion chords in the frame of the key of C major: CM, C6, and C64 based on Figured Base Notation https://en.wikipedia.org/wiki/Inversion_(music)#Figured_bass https://en.wikipedia.org/wiki/Inversion_(music)#Figured_bass

recursive 2y ago
Interesting. Coming from a cover band/local small-time musician, C6 means C-E-G-A. In other words, C with an added 6 on top. The charts I play from generally don't have any inversion information on them, and I probably play different inversions each time.
- epcoa 2y ago
  This is unfortunately one of the ambiguities in notation. But usually not a problem because it should be quite clear when figured bass is being used. In jazz/pop notation inversions are indicated with slash chords.
epcoa 2y ago
For what it is worth it’s not wrong to say that the triad where E is the root would be Em#5. The inversions you point out still have the same root (C) even if the bass is different. But I agree you’ve identified the fundamental problem: we cannot infer the root note and, therefore the name (enharmonics aside), from just a set of notes and attempting to is a fool’s errand. Even with a root note, it's going to be difficult many times to have a sensible answer The key problem with this implementation in addition to not simply taking the root note as input (or a key or scale), appears to be the chord database is pretty spartan, since it doesn't appear it would identify C-E-G as anything other than CMaj. If you want figured bass/slash notation then you'll need to specify that as well (bass note). A number of chord namers take these as additional inputs.
- tunesmith 2y ago
  Em #5 would have a B#, not a C. This isn't a pedantic point; it very much matters if we're trying to be accurate with chord naming. Another example to illustrate how identifying the root is important: C E G A. It's either a C6 or an amin7.
  - epcoa 2y ago
    You're absolutely right about enharmonic equivalents and I could/should have been more precise. However of course the given task of "keys" or pitches -> chords we don't have any information about this, enharmonic equivalents are equivalent. The point is, if the C/B# note (we don't know which one), G and E are given to you and I tell you to root is "E", then the chord could be Em#5. If it really were unambiguously C then it would be a Em♭6(no 5). Point in any case is you need more to go on (at the very least a scale). I think the point that root and bass should not be conflated is also valid.
    - shermantanktop 2y ago
      Chords in isolation are an academic exercise. In the context of an overall chord progression, this “enharmonic ambiguity” normally disappears completely, at least for mainstream jazz, pop, rock, folk, most classical, etc. - you know, the music that people who weren’t music majors actually like.
      - epcoa 2y ago
        Sure, but I certainly haven't been proposing that naming chords based on identifying pitches on a standard keyboard with no other context is suitable, quite the opposite (fool's errand in my original comment). In the confines of the problem statement, it's all enharmonic ambiguity, and that's the point. The Em#5 example was based off the one in the original article, but a much more down to earth one would be F♯ and G♭. Not exactly obscure chords and illustrative of the fundamental issue with this method.
  - pistoleer 2y ago

by mjg2 2y ago

recursive 2y ago

Interesting. Coming from a cover band/local small-time musician, C6 means C-E-G-A. In other words, C with an added 6 on top. The charts I play from generally don't have any inversion information on them, and I probably play different inversions each time.

epcoa 2y ago
This is unfortunately one of the ambiguities in notation. But usually not a problem because it should be quite clear when figured bass is being used. In jazz/pop notation inversions are indicated with slash chords.

epcoa 2y ago

For what it is worth it’s not wrong to say that the triad where E is the root would be Em#5. The inversions you point out still have the same root (C) even if the bass is different. But I agree you’ve identified the fundamental problem: we cannot infer the root note and, therefore the name (enharmonics aside), from just a set of notes and attempting to is a fool’s errand. Even with a root note, it's going to be difficult many times to have a sensible answer The key problem with this implementation in addition to not simply taking the root note as input (or a key or scale), appears to be the chord database is pretty spartan, since it doesn't appear it would identify C-E-G as anything other than CMaj. If you want figured bass/slash notation then you'll need to specify that as well (bass note). A number of chord namers take these as additional inputs.

tunesmith 2y ago
Em #5 would have a B#, not a C. This isn't a pedantic point; it very much matters if we're trying to be accurate with chord naming. Another example to illustrate how identifying the root is important: C E G A. It's either a C6 or an amin7.
- epcoa 2y ago
  You're absolutely right about enharmonic equivalents and I could/should have been more precise. However of course the given task of "keys" or pitches -> chords we don't have any information about this, enharmonic equivalents are equivalent. The point is, if the C/B# note (we don't know which one), G and E are given to you and I tell you to root is "E", then the chord could be Em#5. If it really were unambiguously C then it would be a Em♭6(no 5). Point in any case is you need more to go on (at the very least a scale). I think the point that root and bass should not be conflated is also valid.
  - shermantanktop 2y ago
    Chords in isolation are an academic exercise. In the context of an overall chord progression, this “enharmonic ambiguity” normally disappears completely, at least for mainstream jazz, pop, rock, folk, most classical, etc. - you know, the music that people who weren’t music majors actually like.
    - epcoa 2y ago
      Sure, but I certainly haven't been proposing that naming chords based on identifying pitches on a standard keyboard with no other context is suitable, quite the opposite (fool's errand in my original comment). In the confines of the problem statement, it's all enharmonic ambiguity, and that's the point. The Em#5 example was based off the one in the original article, but a much more down to earth one would be F♯ and G♭. Not exactly obscure chords and illustrative of the fundamental issue with this method.
- pistoleer 2y ago