Harken Microtonal Composer is a multitrack notation and playback tool for composing music in 24-TET (24-tone equal temperament). Write music using Harken Numeric Notation with quarter-tone support, create arrangements with up to 8 simultaneous staves, explore Spectral Harmony by mixing natural and quarter-sharp pitches, and assign different instruments for rich microtonal ensemble playback.
24-TET divides the octave into 24 equal steps instead of 12. Each step is 50 cents (half of a semitone), allowing you to access quarter-tones used in Arabic maqam, Indian raga, Persian dastgah, and contemporary spectral composition.
Natural Pitches (0-11): Standard chromatic scale starting from your tonic.
Example (Tonic = C):
Quarter-Sharp Modifier (+): Adds 50 cents (quarter-tone) to any pitch.
Examples:
0+ — C quarter-sharp (50¢ above C)6+ — F# quarter-sharp (50¢ above F#)10+ — A# quarter-sharp (50¢ above A#)The complete 24-TET chromatic scale:
0, 0+, 1, 1+, 2, 2+, 3, 3+, 4, 4+, 5, 5+, 6, 6+, 7, 7+, 8, 8+, 9, 9+, 10, 10+, 11, 11+
Parenthetical Notation: Enclose multiple pitch classes in parentheses for simultaneous attack (chords/intervals).
Syntax: (pc1,pc2,pc3,...)duration
Examples:
(0,4,7)w — C major triad, whole note(0,3+,7,10)h — Spectral minor 7th (quarter-sharp 3rd), half note(0+,4+,7+)q — Uniform quarter-sharp major triad, quarter note(2,6+,9)e — Mixed natural/quarter-sharp chord, eighth noteOctave shifts within chords: Apply ^ or _ to individual pitches.
(0,4,7^)h — Major triad with high 5th(0_,3+,7,10)w — Spectral minor 7th with bass rootSequential vs. Simultaneous:
0,4,7 — Sequential (arpeggio): three separate attacks(0,4,7) — Simultaneous (chord): all three pitches at onceWhat is Spectral Harmony?
The practice of selectively applying quarter-tone inflections to individual voices within traditional chord structures, creating timbral color while maintaining harmonic coherence.
Techniques:
1. Mixed Natural + Quarter-Sharp: Use quarter-sharps on specific chord tones for spectral color.
(0,3+,7,10)w — Spectral minor 7th (quarter-sharp on the 3rd)(0,4+,7,10)h — Spectral dominant 7th (quarter-sharp on the 3rd)(0,3+,7,10+)q — Spectral minor 7th (quarter-sharps on 3rd and 7th)2. Uniform Quarter-Sharp: Raise entire chord by 50 cents for shimmering coherence.
(0+,4+,7+,10+)w — Uniform quarter-sharp dominant 7th(0+,3+,7+)h — Uniform quarter-sharp minor triadCompositional Tip: Natural pitches (0-11) anchor the harmony. Quarter-sharps (0+-11+) add spectral color. Experiment with different combinations to discover unique voice-leading colors.
Letters (additive):
w — whole noteh — half noteq — quarter notee — eighth notes — sixteenth notet — thirty-second note. — dot (adds 50% duration)Examples:
0h — C natural, half note4+q. — E quarter-sharp, dotted quarter7w — G natural, whole note0+qe — C quarter-sharp, quarter + eighth (3 eighths total)6+e — F# quarter-sharp, eighth noteDefault: If no duration letter, note gets one slot (one quarter-note beat in 4/4).
Format: [beats/note-value] or [beats/note-value:subdivision]
Examples:
[4/4] — 4 quarter-note beats (4 slots per bar — this is the default)[3/4] — 3 quarter-note beats (waltz)[6/8] — 6 eighth-note beats (compound meter)[4/4:8] — 4/4 with 8 subdivisions per bar (eighth-note grid)[12/8:12] — 12/8 with 12 subdivisions (twelve eighth-notes)[12/8:24] — 12/8 with 24 subdivisions (twenty-four sixteenth-notes)24-TET Note: A complete 24-pitch cycle requires 24 rhythmic slots. Use [12/8:12] for 24 eighth-notes across 2 measures, or [12/8:24] for 24 sixteenth-notes in 1 measure.
Default: If no time signature is written in measure 1, the composition defaults to 4/4 with 4 slots (quarter-note grid).
* — rest (quarter-note slot in 4/4)*h — half-note rest*q — quarter-note rest*w — whole-note rest*e — eighth-note rest^ — up one octave_ — down one octaveExamples:
0^ — C natural, one octave higher6+_ — F# quarter-sharp, one octave lower7^^ — G natural, two octaves higher' — play note at 25% of its written duration (sharp, detached)Example: 0+' — C quarter-sharp, staccato quarter note
~ — sustain previous pitch without re-attack (tie symbol)Examples:
0q~q — C natural quarter tied to another quarter (half note total)|0+h.| |~e,7,4,2| — C quarter-sharp dotted half tied across barline to eighth| — measure separator (optional, visual/code only)Example: |0,4+,7| or 0,4+,7 (both valid)
The Control Panel keypad (⊞ Control Panel → Keypad tab) provides visual pitch entry with a two-row layout:
Top Row — Natural Pitches (0-11):
[0] [1] [2] [3] [4] [5] [6] [7] [8] [9] [10] [11]
Bottom Row — Quarter-Sharps (0+-11+):
[0+] [1+] [2+] [3+] [4+] [5+] [6+] [7+] [8+] [9+] [10+] [11+]
How to use:
Color Coding: Buttons use the Harken ColorMap extended for 24-TET. Natural pitches show full-saturation colors; quarter-sharps show interpolated colors (midway between adjacent naturals).
Harken Microtonal Composer supports up to 8 simultaneous staves for complete ensemble arrangements.
How to manage staves: Click ⊞ Control Panel → Score tab to add/delete/configure staves.
Per-staff settings:
Example multitrack setups:
Each staff can use a different instrument from the sampled library (40+ instruments available). All instruments support 24-TET playback with quarter-tone detuning.
How to assign: Open ⊞ Control Panel → Score tab → select instrument from dropdown for each staff.
Common instruments:
Playback tip: Each instrument sounds immediately on playback with proper 24-TET quarter-tone detuning applied automatically.
Mixer (⊞ Control Panel → Mixer tab):
Playback Controls (main toolbar):
Geometric transformation operations create variations of melodic material while preserving rhythmic structure and quarter-tone relationships. Transform any measure using mathematical operations.
Available Transformations:
How to use: Click ⊞ Control Panel → Transform tab, select target measure, choose operation.
24-TET Note: Transformations operate on the base pitch class (0-11). The quarter-sharp modifier (+) is preserved through all transformations. Example: 0+,3+,7 reflected becomes 0+,9+,5 — the + modifiers stay attached to their transformed pitches.
Export (.hkn format):
"0+", "6+", etc. in the JSONImport:
Workflow tip: Export frequently. Create versions (draft1.hkn, draft2.hkn, final.hkn) to track progress and allow backtracking.
Complete 24-pitch chromatic cycle (2 measures of 12/8:12):
[12/8:12]0e,0+e,1e,1+e,2e,2+e,3e,3+e,4e,4+e,5e,5+e
6e,6+e,7e,7+e,8e,8+e,9e,9+e,10e,10+e,11e,11+e
Spectral minor 7th progression:
[4/4](0,3+,7,10)w|(5,8+,0,3)w|(7,10+,2,5)w|(0,3+,7,10)w
Uniform quarter-sharp melody:
[4/4]0+q,3+q,7+q,10+h
Mixed natural and quarter-sharp arpeggio:
[4/4]0e,3+e,7e,10+e,7e,3+e,0e,*e
Spectral chord voicing with octave shifts:
[4/4](0_,3+,7,10+)w|(5_,8+,0,3)w
Hamiltonian cycle on pentagonal icositetrahedron (24-TET "cycle of fifths"):
[12/8:12]0,6+,1,7+,2,8+,3,9+,4,10+,5,11+
6,0+^,7,1+^,8,2+^,9,3+^,10,4+^,11,5+^