How Orphere Names Every Chord: A System Built from Intervals and Degrees
If you’ve ever stared at a chord symbol in a score and wondered what exactly it contains, or scrolled through a chord library looking for a voicing you could hear but couldn’t name, you’re not alone. Most tools give you a fixed dictionary of chord names. Orphere takes a different approach: every chord name is generated from first principles, built up from intervals and scale degrees. The result is a system where the name always tells you exactly what’s in the chord, and where no two collections of notes share a name.
The format
Every chord name in Orphere follows one pattern:
Root Note + Chord Type
“C maj7” is the root note C combined with the chord type “maj7”. “Db min7b5” is Db combined with “min7b5”. The root tells you the harmonic centre of the chord; the chord type tells you what intervals are built around it.
The root can be any note: C, C#, Db, D, and so on. The chord type encodes exactly which intervals are present, which are altered, and which are deliberately absent.
Starting from intervals
An interval is the distance between two pitches: a minor third, a perfect fifth, an augmented fourth. Each interval has a number (1st through 7th), a quality (diminished, minor, major, perfect, augmented), and an implied size in semitones.
From each interval we derive a degree, defined simply as the position a note occupies relative to the root. A minor third gives us degree “b3”. A perfect fifth gives us “5”. An augmented fourth gives us “#4”. The accidental (flat, sharp, or natural) comes directly from the interval quality.
Degrees are key-independent: they tell you what’s stacked above the root regardless of which note the root is.
Degrees as building blocks
Orphere recognises 18 eligible chord degrees:
| Degree | Interval | Semitones | Family |
|---|---|---|---|
| 1 | Perfect unison | 0 | Root |
| b2 | Minor 2nd | 1 | 2nd (9th) |
| 2 | Major 2nd | 2 | 2nd (9th) |
| #2 | Augmented 2nd | 3 | 2nd (9th) |
| b3 | Minor 3rd | 3 | 3rd |
| 3 | Major 3rd | 4 | 3rd |
| b4 | Diminished 4th | 4 | 4th (11th) |
| 4 | Perfect 4th | 5 | 4th (11th) |
| #4 | Augmented 4th | 6 | 4th (11th) |
| b5 | Diminished 5th | 6 | 5th |
| 5 | Perfect 5th | 7 | 5th |
| #5 | Augmented 5th | 8 | 5th |
| b6 | Minor 6th | 8 | 6th (13th) |
| 6 | Major 6th | 9 | 6th (13th) |
| #6 | Augmented 6th | 10 | 6th (13th) |
| bb7 | Diminished 7th | 9 | 7th |
| b7 | Minor 7th | 10 | 7th |
| 7 | Major 7th | 11 | 7th |
Every chord is a subset of these, always including the root (1), with rules that ensure musical validity. A chord can have at most one type of second, third, fourth, fifth, sixth, and seventh. This results in at most 7 distinct notes. You won’t find a chord with both “3” and “b3”, because that would be a conflicting identity rather than a meaningful voicing. This maps directly to how you’d analyse a chord on paper. Write out the degrees present, and the chord type follows.
Building the name
Given a set of degrees, Orphere constructs the chord type name in three stages.
Stage 1: The core (third and seventh)
The combination of third and seventh determines the chord’s primary identity, as these are considered characteristic tones:
| Third | Seventh | Name |
|---|---|---|
| 3 | b7 | dom7 |
| b3 | b7 | min7 |
| b3 | 7 | minmaj7 |
| 3 | 7 | maj7 |
| b3 | bb7 | dim7 |
If there’s a third but no seventh, the name is simply “maj” or “min”. If there’s a seventh but no third, the seventh quality leads and “no3” is appended, for example “b7no3”. If neither is present, the name begins with “no3”.
Stage 2: The fifth
Next comes the fifth:
| Fifth present | Suffix appended | Example |
|---|---|---|
| Perfect fifth (5) | None | maj7 |
| Augmented fifth (#5) | #5 | maj#5 |
| Diminished fifth (b5) | b5 | min7b5 |
| No fifth | no5 | dom7no5 |
So “maj#5” is a major triad with a raised fifth (the augmented triad). “min7b5” is a half-diminished chord. “dom7no5” omits the fifth, leaving just the root, third, and flat seventh, common in jazz arranging and useful when you want to keep the texture lean.
Stage 3: Extensions
The upper degrees (2nd, 4th, and 6th) map to their compound interval names:
| Degree | Extension name |
|---|---|
| 2 (or b2, #2) | 9 (or b9, #9) |
| 4 (or b4, #4) | 11 (or b11, #11) |
| 6 (or b6, #6) | 13 (or b13, #13) |
The accidental carries over directly. A b2 degree becomes “b9” in the chord name; a #4 becomes “#11”. Multiple extensions concatenate: a dominant seventh with a flat nine and sharp eleven is “dom7b9#11”. If you’re writing for orchestra or large ensemble and need to specify exactly which colour tones the winds or brass are covering, this level of detail saves you from ambiguity.
Putting it together
The full chord name combines the root note with the type name:
C maj7: degrees 1, 3, 5, 7
D min7b5: degrees 1, b3, b5, b7
G dom7#9: degrees 1, 3, 5, b7, #2 (the #2 becomes #9)
A b7no3: degrees 1, 5, b7 (third absent)
F min7no5b9: degrees 1, b3, b7, b2 (fifth absent, flat nine)
As you can see, every component describes exactly what’s present.
Why “no3” and “no5” matter
Traditional chord naming often leaves gaps. “C5” might mean a power chord, but in some notation systems it could be read differently. “Csus” tells you the third is replaced but not always what replaced it.
Orphere’s approach removes that ambiguity. We assume a chord has a third and a fifth unless we add “no3” to indicate the third is absent and “no5” to indicate the fifth is absent. For composers working with sparse voicings, open structures, or orchestral doublings where certain chord tones are deliberately left out, this precision is essential. For example, “dom7no3no5” is unambiguously a root and flat seventh, nothing else.
The combinatorial engine
Orphere doesn’t rely on a hand-curated chord dictionary. Instead, it generates every valid combination of the 18 eligible degrees, subject to these constraints:
- The root (1) is always present
- At most one variant of each degree number (one type of third, one type of fifth, etc.)
- No duplicate semitone positions
- Between 1 and 7 total degrees
This produces a comprehensive set of chord types that covers standard triads and sevenths, extended and altered dominants, quartal voicings, and every sparse or unusual structure in between.
Aliases
Many chord types are known by more than one symbol. Orphere handles this by matching each generated chord type against established music theory definitions and pulling in familiar aliases. For example, “maj7” also recognises “M7” and the delta symbol. “dom7” recognises “7”. “min7b5” recognises the half-diminished symbol. When you search for a chord in the studio, Orphere matches against both the primary name and all aliases, so you can find what you’re looking for regardless of which notation convention you’re used to.
The complete picture
The result is a naming system that is both complete and consistent. Every chord you encounter in Orphere has a name that tells you exactly what it contains, built from the same rules, with no special cases.