Major Components

GUI

• Built with Qt, contains all of the interface widgets, which are listed in a separate table.
• The GUI sends events to the controller as Qt signals, which are received by slot methods.
• A slot method could trigger an interface update, or modify the application, or both.

Interface

• None, the operating system supplies Events which are handled by GUI widgets.

References

• Controller

Controller

• The Controller is responsible for updating the application based on User actions.
• Provides Qt callback functions for each Widget known as slots, which are triggered by signals.
• If the signal denotes a change in the model, the controller will call the interface method of the appropriate class.

Interface

• AddMusician() -- passes a musician to the Conductor, who adds it to the Ensemble.
• RemoveMusician() -- passes a musician to the Conductor, who removes it from the Ensemble.
• FilterMusicians(tags) -- references MusicianDirectory, and gets a list of Musicians with descriptions matching the given tags.
• Play() -- Starts the CoreDriver, which causes audio to play.
• Pause() -- Stops CoreDriver, which stops triggering audio playback.
• UpdateSongInfo() -- Changes a value of SongInfo, such as the Key.

References

• MusicianDirectory
• Conductor
• CoreDriver
• SongInfo

CoreDriver

• The CoreDriver is responsible for synchronizing the Conductor and the Parser.
• It contains a timer which ticks on intervals which evenly divide a song measure into rhythmic units.
• The Conductor and Parser listen for these ticks to increment the current position in the Score.
• The CoreDriver implements the Play/Pause functionality: if it stops emitting ticks, the Conductor and Parser do not do anything.

Interface

• Run() -- causes the internal Timer to start emitting ticks based on the song tempo and time signature.
• Halt() -- stops the internal Timer.
• Pulse() -- listenable method, called when the Timer ticks.

References

• SongInfo
• Score

Parser

• Moves through the Score, and processes notes from the Score as FluidSynth signals.
• Its position is updated on each CoreDriver Pulse.
• If there is a note to play on a given pulse, send a signal to FluidSynth.
• Controlled by CoreDriver Pulse().

Interface

• OnPulse() -- Listens for a Pulse event, and plays any notes which fall within that pulse.

References

• Score
• CoreDriver

Conductor

• Cues Musicians from the Ensemble to add their parts to the score.
• Controlled by CoreDriver PulseEvent.
• Adds and removes musicians from the ensemble.

Interface

• OnPulse() -- Listens for a Pulse event, and cues musicians to compose for a specified duration.
• AddMusician() -- adds a new Musician to the Ensemble.
• RemoveMusician() -- removes a Musician from the Ensemble.

References

• Score

SongInfo

• Contains tempo, key signature, time signature which are currently valid.
• The interface writes modifications to the song here, which are applied when a new measure is loaded by CoreDriver.

Interface

• UpdateTempo() -- changes the beats per minute.
• UpdateKeySignature() -- changes the key signature, and whether the key is major/minor.
• UpdateTimeSignature() -- changes the time signature.

References

• None

MusicianDirectory

• Contains Musician class references and descriptions.
• Used to filter Musicians based on tags (genre, instrument, category) to support GUI.

Interface

• Filter(tags) -- given a set of tags, returns a list of musicians which contain all of those tags.

InstrumentDirectory

• Contains family hierarchy and filterable list of instruments.

Interface

• GetParent(instrument) -- given an instrument, returns the parent of that instrument in a familial sense.

  For example, a djembe's parent is a hand drum, a hand drum's parent is a drum, a drum's parent is percussion instrument, ...and so on.

Ensemble

• A list of musicians. Contains no other data at this time.

Interface

• Get()
• Add()
• Remove()

References

• Musician

Musician

• Has a list of properties such as 'Energy' or 'Bowed.'
• Has an instrument which is a key in the InstrumentDirectory. This key is written into the score. Used also so the Parser can look up which SoundFont to use.

Interface

• SetProperty(key, value) -- changes a Musician parameter such as Energy or Complexity.
• Compose(duration) -- instructs the Musician to add its performance to the score. Duration specifies at least how far into the future the Musician should compose (ie one full beat)

References

• Instrument
• InstrumentDirectory

Instrument

• Simply a key for lookup in InstrumentDirectory()

Interface

• None

References

• None

Score

• Contains Staffs, which contain StaffMeasures. Staffs is rarely accessed by anything, just used to add or remove a Musician.
• Contains StaffMeasures.

Interface

• GetStaff(Musician) -- returns the staff belonging to a specific Musician.
• GetScoreSlices() -- gets the head of the ScoreSlice linked list.

References

• Staff
• ScoreSlice

Staff

• Contains Measures.
• Not intended to be used by any components except for Score.

Interface

• GetMeasures() -- returns the head of a linked list of Measure.

References

• Measure

ScoreSlice

• Represents a vertical slice of a piece of sheet music.
• Stores a key signature and a time signature.
• Contains Measures indexable by Musician.

Interface

• GetMeasures() -- a list of measures which are played simultaneously.
• Next() -- the next StaffMeasure, moving forward in time.
• Previous() -- the previous StaffMeasure, moving backward in time.

References

• Measure
• Musician

Measure

• Has next() and previous() methods to move forward or backward in Score.
• Contains Notes, implemented as a doubly linked list.

Interface

• Next() -- return the measure after this one in the Score.
• Previous() -- return the measure before this one in the Score.
• GetNotes() -- get the Notes which are in this measure.
• AppendNote(Note) -- adds a Note to the end of this Measure's Notes.

References

• Note

Note

• A note represents a tone and its rhythmic description in the Score.

Interface

• SetVelocity() -- how hard the note is struck.
• SetDuration() -- the musical description of the Note's rhythmic value.
• SetTone(tone, octave) -- describes the Note frequency.
• SetSlur(slur, type) -- whether or not this note blends into the next note, and how to shift the pitch.
• Previous() -- get the previous note(s)
• Next() -- get the next note(s)

References

• None