music-db

Music Database is an attempt to make an encyclopedic database of scales based on William Zeitler classification.

This project consists of:

• postgres database seed generator
• music theory data API

The project is bundled as a docker cluster containing

• postgres 16 database prefilled with music data
• HTTP REST API server

Features:

• 12 semitones per octave
• Supports 1490 scales
• Supports 17880 keys
• Supports 936 chords
• Keys mode detection
• Scale balance detection and center of gravity
• Scale perfections and imperfections detection
• List chords of a note of a given key
• List keys that are applicable to that chord
• Scale rotational symmetry detection
• Scale reflective symmetry detection
• Scale cardinality
• Chord cardinality
• Ian Ring's numbering system for pitches, chords and scales
• Scale and key illustration as pitch class bracelet diagram
• Scale and key illustration as circle of fifth bracelet diagram
• Scale, key and chord and illustration using keyboard
• Synthesize chord as WAV file (grand piano)

Running test

make test

Building

To get database up and running

docker-compose up

Navigate to http://localhost:3000/api/docs/ to see swagger docs

Example Queries

Listing Pitches of a key

SELECT k.name AS key,
       p.name AS pitch,
       kp.pitch_id
FROM key_pitches kp
         JOIN keys k ON kp.key_id = k.id
         JOIN pitches p ON kp.pitch_id = p.id
WHERE k.name = 'CNaturalIonian'
ORDER BY kp.id;

List All Chords for C Major

SELECT k.name AS key,
       p.name AS pitch,
       c.name AS chord
FROM key_pitch_chords spc
         JOIN keys k ON spc.key_id = k.id
         JOIN chords c ON spc.chord_id = c.id
         JOIN pitches p ON spc.pitch_id = p.id
WHERE k.name = 'CNaturalIonian';

Query by API

Listing Pitches

$ curl localhost:3000/api/v1/theory/pitches
[{"id":1,"name":"CNatural"},{"id":2,"name":"CSharp"},{"id":3,"name":"DNatural"},{"id":4,"name":"DSharp"},{"id":5,"name":"ENatural"},{"id":6,"name":"FNatural"},{"id":7,"name":"FSharp"},{"id":8,"name":"GNatural"},{"id":9,"name":"GSharp"},{"id":10,"name":"ANatural"},{"id":11,"name":"ASharp"},{"id":12,"name":"BNatural"}]

Query by API

API is accessible at port 3000

Pagination via query string page and per_page

Pitches

Method	Path	Description
GET	/api/v1/theory/pitches/{:id}/chords	List chords from pitch
GET	/api/v1/theory/pitches/{:id}/keys	List keys from pitch
GET	/api/v1/theory/pitches/{:id}/scales	List scales from pitch
GET	/api/v1/theory/pitches/{:id}	Get pitch
GET	/api/v1/theory/pitches	List pitches

Chords

Method	Path	Description
GET	/api/v1/theory/chords/{:id}/keys	List chord keys
GET	/api/v1/theory/chords/{:id}/pitches	List chord pitches
GET	/api/v1/theory/chords/{:id}/quality	Get chord quality
GET	/api/v1/theory/chords/{:id}/scales	List chord scales
GET	/api/v1/theory/chords/{:id}	Get chord
GET	/api/v1/theory/chords	List chords
GET	/api/v1/theory/chords/{:id}/illustrations/keyboard	Illustrate the chord using keyboard
GET	/api/v1/theory/chords/{:id}/illustrations/wav	Synthesize the chord as WAV file

Scales

Method	Path	Description
GET	/api/v1/theory/scales/{:id}/chords	List scale chords
GET	/api/v1/theory/scales/{:id}/keys	List scale keys
GET	/api/v1/theory/scales/{:id}/pitches	List scale pitches
GET	/api/v1/theory/scales/{:id}	Get scale detail
GET	/api/v1/theory/scales	List scales
GET	/api/v1/theory/scales/{:id}/illustrations/pitch_class_bracelet	Illustrate the scale as a pitch class bracelet diagram
GET	/api/v1/theory/scales/{:id}/illustrations/circle_of_fifth_bracelet	Illustrate the scale as a circle of fifth bracelet diagram
GET	/api/v1/theory/scales/{:id}/illustrations/keyboard	Illustrate the scale using keyboard

Keys

Method	Path	Description
GET	/api/v1/theory/keys/{:id}/chords	List key chords
GET	/api/v1/theory/keys/{:id}/modes	List key modes
GET	/api/v1/theory/keys/{:id}/pitches	List key pitches
GET	/api/v1/theory/keys/{:id}	Get key detail
GET	/api/v1/theory/keys	List keys
GET	/api/v1/theory/keys/{:id}/illustrations/pitch_class_bracelet	Illustrate the key as a pitch class bracelet diagram
GET	/api/v1/theory/keys/{:id}/illustrations/circle_of_fifth_bracelet	Illustrate the key as a circle of fifth bracelet diagram
GET	/api/v1/theory/keys/{:id}/illustrations/keyboard	Illustrate the key using keyboard

Bracelet Diagram

Pitch Class Bracelet Diagram

C Natural Ionian illustrated as pitch class bracelet diagram

Circle Of Fifth Bracelet Diagram

C Natural Ionian illustrated as circle of fifth bracelet diagram

Keyboard

FNaturalIonian illustrated using keyboard