5.2 Events

Objects with times and durations are referred to in this documentation as “events.” There are four types of events in FOMUS: notes, rests, marks and measures. Note and rest events represent notes that appear in the score while mark events represent articulations, dynamics and other markings. A measure event specifically represent the first measure in which some change occurs at the metrical level (e.g., a key signature change, time signature change, or double barline).

All events have time and duration parameters. Times and durations are expressed in what is referred to in this documentation as “beats,” a unit which is (mostly) unassociated with rhythmic spelling until after FOMUS has finished processing everything. One beat represents a consistent unit of time irrespective of time signature, metronome markings or any other notational convention. The first time point in a score is always 0 (i.e., there are no negative time values).

Measures have a time and duration like any other event type and aren't defined using time signatures. A measure defined with a duration of 2, for example, occupies 2 beats regardless of whether it's a 2/4 or 4/8 measure or whether a beat is notated as a quarter note or an eighth note. It is possible to specify time signatures if desired, though this is slightly less flexible. By defining measures in terms of duration you can easily change time signatures, rhythmic spellings, and even manipulate the layout of measures in the score while leaving the essential musical information (the relative times and durations) intact.

Each frontend has a unique way of defining events along with their arguments. In .fms files all of the arguments are given as lists of parameters and values (see Tutorial). In CM, they can appear in processes and are sent to FOMUS like other scheduled events (a floating point time stamp is added automatically). In Pure Data, note events are sent by creating a fomus instance, passing parameters to the appropriate inlets and passing a bang message to the leftmost inlet to send the note event.

A complete list of FOMUS's events are given here:

•Measure Events

• name: meas
• parameters:

  time

  Time offsets for measures are quantized to the nearest value determined by the meas-beatdiv setting.
  

  duration

  Durations for measures are quantized to the nearest value determined by the meas-beatdiv setting. If the measure contains the measdur setting, then the duration is ignored and the value for measdur is used instead (this allows you to fix the measure's duration in a measdef definition). The time signature is determined either by lists of time signatures that you provide (FOMUS chooses the first valid time signature it finds from the timesigs setting) or by calculating it from the timesig-den setting. If a time signature is explicitly specified using the timesig setting then the duration is ignored (and recalculated according to timesig and the value of beat).
  

  (+ settings)

  A measure either contains its own settings or gets them from a measdef object that it is associated with. Due to the way meas and measdef objects are implemented, you cannot define a measure that contains a measdef and add additional settings on top of that.

In FOMUS you only need to define a measure at points in the piece where a change occurs (e.g., the time signature, key signature, or some setting that changes the behavior for a whole section). FOMUS fills in all of the areas where measures aren't explicitly defined by repeating the ones that are. FOMUS also adjusts durations (and time signatures) to resolve conflicts. This means you can place measures wherever you want without regard to whether or not they cause overlaps. FOMUS automatically truncates or expands them as necessary.

By default, measures are assigned to all parts when they are created. To assign a measure to only a subset of parts (to create polymeters, for example), use the measparts setting.

•Note Events

• name: note
• parameters:

  part

  This is the ID of a part defined in the score. A note event must belong to a part. If none is given, the note is assigned to a default part (which has an ID of ‘default’).
  

  voice

  This can be a single integer (greater to or equal to one) or a list of integers specifying several voices for FOMUS to choose from. If none is given the default is 1.
  

  time

  This can be a floating point or rational number (i.e., any numeric data type). Times and durations for note events are quantized using an algorithm that finds the nearest fit by searching through combinations of metrical divisions and tuplets.
  

  grace

  Grace notes exist in a subset of time called “grace time.” To define a grace note, you must give both a time and a grace time in addition to a duration (which is interpretted as a “grace duration”). The grace note is placed before any regular (non-grace) events at the given time. The grace time (given by the grace parameter) and grace duration (which is given by the duration parameter) determine where the grace note appears relative to other grace notes at that location, and is notated as if the grace time and grace duration were real time and duration values. (A grace time of 0 and grace duration of 1/4 with default settings creates a sixteenth grace note in the same way that a regular note with duration 1/4 creates a regular sixteenth note. Another grace note with grace time 1/4 and duration 1/4 would immediately follow the first grace note.) Grace time, like regular time, must be 0 or greater.
  

  duration

  Duration is usually specified as a number greater than zero. It can optionally be a string (e.g., “q” or “e.”) which is mapped to a number according to the settings dur-symbols, dur-dots, dur-tie and tuplet-symbols. These symbols are there for convenience but can also be misleading since they are mapped directly to numbers and don't necessarily reflect what appears in the output. Changing the value of the setting beat, for example, would cause a discrepancy between the symbols and the rhythmic spellings that result.

  If the duration is equal to zero, then FOMUS chooses a duration that is easy to read and doesn't involve a tie. This is appropriate for percussion attacks and certain techniques like pizzicato strings where the release occurs immediately after the attack. In .fms files there are also + (“fill forward”) and - (“fill backwards”) symbols that are instructions for FOMUS to extend the duration up to the next (or previous) event in the same voice.
  

  pitch

  The pitch can either be a number, a string (e.g., “cs4”) or the ID of a percussion instrument. Note symbols can be customized with the note-symbols, note-accs, note-microtones and note-octaves settings. Percussion instrument IDs only have meaning when used in parts with instruments that contain percinst objects.

  Floating point and non-integers are quantized according to the value of the quartertones setting.
  

  dyn

  This is a dynamic level specified as a number, the range of which is given by the dyn-range settings. If the dyns setting is set to ‘yes’, dynamic values are translated to dynamic text symbols and crescendo/diminuendo wedges. If dyns is ‘no’, this value is ignored.
  

  marks

  This is a list of marks to be associated with the note. Marks can be articulations, technique indications, text strings, octave change signs, phrase markings, dynamic markings, dynamic wedges, tremolos, harmonics, etc.. A list of valid marks is given in Marks.

  Some marks come in begin/end pairs and are referred to as spanners. If a begin spanner mark is given but no end mark is given, FOMUS assumes that the end is at the beginning of the next spanner mark (or the end of the score). The opposite is also true—if an end mark is missing a begin mark, FOMUS assumes the beginning occurs right after the last end.

  Many marks take an optional string or number parameter that alters how the mark is processed or specifies some text to appear in the score. Some marks also come in pairs (like pizz and arco) or in groups (like pp, mp, mf, etc.) so that FOMUS can sort them out and make sure they appear correctly in the score.
  

  (+ settings)

•Rest Events

• name: rest
• parameters:

  part
  

  voice

  A list of voices doesn't represent a choice in this case—instead it specifies all of the voices the rest belongs to.
  

  time
  

  grace

  Rests can also have a grace value, though FOMUS currently ignores grace note rests.
  

  duration
  

  marks
  

  (+ settings)

You should almost never need to create rest events—FOMUS creates all of the rests for you. One reason for defining one is to include a fermata in the score at some location. Rests can also have effects on some calculations such as the fill-forward and fill-backward durations mentioned above or the pruning of overlapping notes.

•Mark Events

• name: mark
• parameters:

  part
  

  voice

  This is the voice or voices that the mark event affects. A mark event with slur begin/end marks and a voice list of ‘(1 2)’, for example, applies two separate slur marks to voices 1 and 2.
  

  time
  

  grace
  

  duration
  

  marks

  The marks in this list are applied to note events that fall within the mark event's time range. A few spanner marks (like crescendo/decrescendo wedges), however, are unattached to any note events if detach is set to ‘yes’.
  

  (+ settings)

A mark event represent a mark or a group of marks that exists separately from note or rest events. This allows you to generate patterns of articulations separately or attach spanner marks without having to calculate exactly which notes the begin/end marks belong to. The marks are applied to note events at a point in FOMUS's processing after voices have been sorted out. Two settings, left and right offer precise control over which note events are affected.

If a mark event contains a begin mark, this is only applied to a note or notes at the beginning of the mark event. End marks are similarly applied only to notes at the end time of the mark event. All other marks (i.e., non-spanner marks) are applied to every note that falls within the range of the mark event.

As mentioned above, a few spanner marks (like crescendo/decrescendo wedges) are unattached to any note events if detach is set to ‘yes’. This is accomplished by creating an invisible voice full of rests in the score and placing the marks in this voice.

5.2.1 Object Hierarchy

A diagram of how FOMUS's objects contain or reference each other is shown below.

Figure 5.1: FOMUS Object Hierarchy

This shows, for example, that a part “contains” an instrument (or references one) while a measure contains notes, rests and marks.