Architecture

ArchitectureVersionThree

Here is a scattered doc of the augmented architecture I showed today. (It's a really rough draft, but the ideas are there.) -- Travis Apr. 21

Here is a diagram of how things fit together.

Front End

GUI

• Contains many widgets, as described below.

Controller

• Provides callbacks to update the interface. If the interface change affects the model, it communicates with the application.

FluidSynth

• Given signals, produces audio output.

Core

Application

• Loads static data: MusicianDirectory, InstrumentTree, and SoundFileMap.
• Notifies the conductor when an instrument is added or updated.
• Updates SongInfo when the user changes it.
• Tells SongControl if playback has paused or unpaused.

SongControl

• Keeps a tight loop of audio playback:

  • Tells Parser to parse the current StaffSubMeasure
  • Tells Conductor to fill the next StaffSubMeasure
  • Old = Current
  • Current = Next
  • NextStaffMeasure.SongInfo is set to SongInfo if this is the last StaffSubMeasure (this includes tempo, key, time signature)
  • Wait out the duration of Old, then repeat

• Reads from Score, passes Score data on to Conductor and Parser for composition and output, respectively.
• This module is responsible for a responsive feel by keeping the Conductor and Parser just barely separated.

Parser

• Sends note signals to FluidSynth from a StaffSubMeasure note list.

Conductor

• Adds, removes, and updates musicians in the Ensemble.
• When given a StaffSubMeasure, assigns each Musician a SubMeasure to fill with notes, one at a time.

Conductor (edit)

• Adds, removes, and updates Musicians
• Tasks Musicians with generating music by SubMeasure

Model

Ensemble

• List of Musicians.

Musician

• Has List of Instruments.
• Generates notes for a SubMeasure.
• References InstrumentTree to learn "is-a" information about Instrument.

Musician (edit)

• Delegates making of music to attached Instrument
• Checks result for correctness
• Capable of learning

Instrument

• A simple (string?) identifier for a type of musical instrument that is a node in InstrumentTree.

Instrument (edit)

• Generates notes for a SubMeasure.

SongInfo

• Tempo
• Key
• Time Signature
• Redundant, because SongControl updates each StaffMeasure with this info. Kept separate to decouple components.

Score

• Contains StaffMeasures

Staff Measure

• A vertical division of a score. Contains all the measures at a given time interval (what you see if you look down instead of across a score sheet).
• Contains StaffSubMeasures
• Contains SongInfo
• Contains Instrument

StaffSubMeasure

• Contains SubMeasures

SubMeasure

• Contains Notes

Note

• Velocity
• Duration (quarter note, half note....)
• Tone
• Other characteristics....

Static Data

MusicianDirectory

• Mainly used by the InstrumentSelector to filter Instruments
• Loaded by the application on startup

InstrumentTree

• Hierarchical classification of Instruments, to lookup the parents of a given Instrument.
• Used by Musician to understand an unknown Instrument.
• Loaded by the application on startup

SoundFileMap

• Maps Instruments to their respective voice or sound file, i.e. SoundFont
• Loaded by the application on startup

List of widgets