vault backup: 2026-01-03 18:55:50

music-theory.md

@@ -6,15 +6,6 @@ tags: []
 ---
 # Music Theory
 
-```mermaid
-classDiagram
-    class PitchSpelling {
-        PitchLetter letter
-        Accidental acc
-        Octave octave
-    }
-```
-
 ## Note
 
 ### Pitch
@@ -28,7 +19,7 @@ if they represent the same pitch.
 
 #### Pitch Class
 
-| mod 12 | name  | 
+| mod 12 | name  |
 | ------:| ----- |
 |      0 | C     |
 |      1 | C♯/D♭ |
@@ -60,7 +51,7 @@ There is no missing half between E and F or B and C,
 because there are no halves at all.
 C# is as legitimate a pitch class as C,
 and in some disciplines, accidentals are marked on every note,
-even "redundantly" in acknowledgement of this fact.
+even "redundantly", in acknowledgement of this fact.
 
 What is meant by the poor terminology is this:
 
@@ -84,22 +75,21 @@ to [minor second](https://en.wikipedia.org/wiki/Minor_second)
 and [major second](https://en.wikipedia.org/wiki/Major_second) respectively,
 which is a [[ambiguity#Category Mistake|category mistake]].
 
-
-5 in 12 1 semitone increments result in augmented unisons.
-2 in 12 2 semitone increments result in diminished thirds.
-
 #### Accidentals
 
 | ascii | unicode | lilypond | Name         |
 | ----- | ------- | -------- | ------------ |
-| bb    | N/A     | eses     | double flat  |
+| bb    | 𝄫       | eses     | double flat  |
 | b     | ♭       | es       | flat         |
 |       | ♮       |          | natural      |
 | #     | ♯       | is       | sharp        |
-| x     | N/A     | isis     | double sharp |
+| x     | 𝄪       | isis     | double sharp |
 
 #### Octave
 
+Octave is a property of staff position, not pitch.
+B♯<sup>3</sup> is enharmonic with C<sup>4</sup>
+
 ### Duration
 
 * beats
@@ -117,7 +107,6 @@ which is a [[ambiguity#Category Mistake|category mistake]].
 Refers to the difference between two pitches.
 Intervals are notated with an en dash (C♯--E).
 
-
 ### Interval Number
 
 Equal to the difference in staff position plus one.
@@ -137,8 +126,6 @@ difference in semitones
 
 The common intervals
 
-
-
 | dP[^1] | dS[^2] | Short | Name           |
 | ------ | ------ | ----- | -------------- |
 | 0      | 0      | P1    | Perfect unison |
@@ -188,20 +175,20 @@ according to some sequence of intervals.
 
 | Key           | Interval Sequence |
 | ------------- |:-----------------:|
-| Major         |   W–W–H–W–W–W–H   |
-| Natural Minor |   W–H–W–W–H–W–W   |
+| Major         |   W--W--H--W--W--W--H   |
+| Natural Minor |   W--H--W--W--H--W--W   |
 
 ### Modes
 
 | Mode       | Interval Sequence |
 | ---------- |:-----------------:|
-| Ionian     |   W–W–H–W–W–W–H   |
-| Dorian     |   W–H–W–W–W–H–W   |
-| Phrygian   |   H–W–W–W–H–W–W   |
-| Lydian     |   W–W–W–H–W–W–H   |
-| Mixolydian |   W–W–H–W–W–H–W   |
-| Aeolian    |   W–H–W–W–H–W–W   |
-| Locrian    |   H–W–W–H–W–W–W   |
+| Ionian     |   W--W--H--W--W--W--H   |
+| Dorian     |   W--H--W--W--W--H--W   |
+| Phrygian   |   H--W--W--W--H--W--W   |
+| Lydian     |   W--W--W--H--W--W--H   |
+| Mixolydian |   W--W--H--W--W--H--W   |
+| Aeolian    |   W--H--W--W--H--W--W   |
+| Locrian    |   H--W--W--H--W--W--W   |
 
 ### Scale
 
@@ -218,4 +205,4 @@ in ascending or descending order.
 * degree 6: submediant
 * degree 7: called the **subtonic** if it is 2 semitones/"a whole step"/a major second below the tonic
     or the **leading tone** if it is 1 semitone/"a half step"/a minor second below the tonic
-* degree 8: tonic
+* degree 8: tonic