This node, which was initially created for test purposes, simply relays MidiStream messages arriving at its input pin to its output pin, numbering ChordOn messages as they arrive (starting from 0). See the example patches below, in which each ChordOn’s index is used to construct an ornament on the chord, using further nodes in the patch. In later patches, this ChordIndexer node has been replaced by the Assistant Performer, which reads ornament numbers from a score.
The starting index is reset to 0 when the node is stopped (e.g. by the StopGo node).

This node sets the OrnamentData for each ChordOn message which arrives at input pin 1 with its OrnamentTypeIndex set, updating the other output pin values accordingly. OrnamentData is data retrieved from a krystal for use in the creation of ornaments, and contains the foloowing fields:

• Input pin 1: MidiStream (ChordOn messages already have their OrnamentTypeIndex set) ChordOn messages arriving at this pin cause the values of the output pins to change. If ChordOn.OrnamentTypeIndex is not null, and greater than -1, it is used to retrieve a OrnamentData object from the krystal. If OrnamentTypeIndex is greater than or equal to the number of IntLists at the given level in the krystal, and the Repeat? value is true, OrnamentTypeIndex modulo the number of IntLists is used. All non-ChordOn messages are simply relayed to the MIDIStream outputPin (Output pin 1)
• Input pin 2: KrystalNamePin. Connect this, for example, to a KrystalNode’s outputPin.
• Input pin 3: level (int)
  It is an error if the level set here is less than or equal to zero, or greater than the number of levels in the krystal. If the level is equal to the number of levels in the krystal, the list of integers in the indexth strand is returned. If the level is less than the number of levels in the krystal, the returned list contains all the integers between the indexth strand at that level and the next strand at that level (or the end of file). So, if the level is 1, the returned List<int> (in the OrnamentData) contains the complete sequence of int values in all the krystal's strands.
• Input pin 4: Repeat? (int) A boolean value (0 = false, other values true) which determines whether or not to repeat the sequence when the current index overflows the number of IntLists at level = Value of input pin 2.
• Output pin 1: MidiStream (ChordOn messages now contain OrnamentData)
  
• Output pin 2: PValue (int) The value of OrnamentData.PValue
• Output pin 3: (string) A string representation of OrnamentData.IntList.
• Output pin 4: (int) The number of IntLists (or values) at the given level (input pin 2) in the krystal.
• Output pin 5: (int) The current index (modulo the IntList count).

Output pins 2, 3, 4 and 5 are simply intended for use while setting up, running and debugging the patch.

• Input pin 1: (MidiStream) Receives MIDI messages from, for example, a KrystalStream node. If an input ChordOn message has its OrnamentData set, it is converted to an ornament which is sent to the output pin in its own background thread. Other messages are sent unchanged. An incoming chordOff message can change the performance of a currently playing ornament, depending on the settings in input pins 3 and 4.
• Input pin 2: (int) rootIndex. The index of the root chord in the OrnamentData.IntList. The root chord has its type defined in Input pin 3, other chords have the type defined in Input pin 4.
  if(rootIndex < 1 )

  rootIndex = 0;

  if(rootIndex >= OrnamentData.IntList.Count)

  rootIndex = OrnamentData.IntList.Count - 1;
• Input pin 3: (int) The note type of the root (see type descriptions below).
• Input pin 4: (int) The note type of the other notes (see type descriptions below).
• Input pin 5: (string) The available durations (each duration must be greater than 9 milliseconds). The string must contain as many comma-separated integers as the domain of OrnamentData.IntList (7 in the patch example below).
• Input pin 6: (string) The available transpositions (-127..+127). The string must contain as many comma-separated integers as the domain of OrnamentData.IntList (7 in the patch example below).
• OutputPin: (MidiStream) A stream of MidiStream messages. Each ornament has its own background thread, independent of the user thread.

Note Type values (integers) for use in Input pins 3 and 4:

When all the Input pins have been connected to this node, and the MidiStream pin (Input pin 1) becomes valid, input pins 5 and 6 are converted to lists of integers: Then, when a ChordOn message arrives at Input pin 1, its OrnamentData.intList and the node’s input pin values are first used to create an Ornament object:
OrnamentData.PValue, which is not used by this node, is also copied to the ornament.

ChordMessages are then sent using the durations stored in the ornament, and subject to the values set in Input pins 2-4.
Each outgoing ChordMessage (ChordOn and ChordOff), is given a pointer to the entire ornament. Each ornament (set of outgoing ChordMessages) is sent in its own background thread, so that it does not interfere with the user thread or any incoming ChordMessages.

Example patch (Simple Ornaments using xk4(7.7.1)-1.krys ):
When a chord is sent to the ChordIndexer, it is indexed and sent on to the KrystalStream node, which uses the index to construct the values pValue and intList from its input krystal. These are sent on to the Ornament node as part of a ChordOn message, and echoed to the KrystalStreamNode’s outputs.
When a ChordOn message arrives at the Ornament node, successive values in the IntList are used, as indexes in the available durations and available transpositions, to construct the chords in the output ornament.
In this patch, the root chord is the first chord in the output, and it has type 0, which means that this chord is always sent (as a ChordOn) whenever it occurs in the IntList, and that its ChordOff is never sent. Other chords in the ornament have type 1, which means that they are always sent as a ChordOn when they occur in the IntList, and their ChordOff is sent after their duration has elapsed.
See xk4(7.7.1)-1.kexp content above.
1. a constant middle C was sent irregularly (by hand) to the patch, waiting for each ornament to complete. 2. a version with overlapping ornaments. The pitch sent by hand changes. 3. a version with overlapping ornaments, using differing major triads as the seed.

This node relays a chord arriving at its leftmost input pin to its output pin, after sending the apropriate MIDI BankChange and PatchChange messages to change the instrument playing it.

• Input pin 1: (MidiStream) Receives MIDI messages and Chords from, for example, an Ornament node
• Input pin 2: (string) AvailableInstrumentsList:
  This string is a comma-separated list of instrument identifiers. Each identifier describes an instrument's bank and patch indices in some sound set. Identifiers can have the following forms:

  <bank>:<patch>	The bank and patch indices are set to the given values.
  <patch>	The bank index is set to 0 (equivalent to 0:<patch>).
  :<patch>	The bank index is set to 0 (equivalent to 0:<patch>).
  <bank>:	The patch index is set to 0 (equivalent to <bank>:0).

  The <bank> and <patch> indices must be integers in the range 0..127.
  By default, the first value in the AvailableInstrumentsList used, but if the chord contains OrnamentData (set, for example, by an Ornament node), the new instrument is set to
  
  AvailableInstruments[OrnamentData.intList[OrnamentData.pValue]].
• Output pin:: (MidiStream) The output MidiStream messages.

Example patch: Adding a SetChordInstrument node to the above krystalStreamOrnament patch just above the Microsoft GS Wavetable Synth OUT node (and changing the output file name inside the output node), gives the following patch:


See xk4(7.7.1)-1.kexp content above.
1. a version produced by sending a middle C irregularly (by hand) to the patch, waiting for each ornament to complete. 2. a version with overlapping ornaments. The pitch sent by hand changes. 3. a version with overlapping ornaments, using differing major triads as the seed.

• Input pin 1: (MidiStream) Receives MidiStream messages. If an incoming ChordOn message has its OrnamentData set, this node first deletes all but the first note in the chord, then adds zero or more notes according to the node’s parameters (see below). Other MIDI messages arriving at Input pin 1 are relayed unchanged.
  
• Input pin 2: (string) AvailableDensities. A string of comma-separated integers in the range 1..128.
  These are the possible densities of notes which can be set in the output chord. By default, the first value in this list is used, but if the chord’s OrnamentData field is set, the density is set to
  
  AvailableDensities[OrnamentData.intList[OrnamentData.pValue]].
  The number of available densities in the AvailableDensities list must therefore be greater than or equal to the domain of the OrnamentData.intList.
  
• Input pin 3: (string) AvailableInversions. A string of comma-separated integers in the range 1 to 2*(N-1), where N is the number of intervals in the AvailableIntervals list. For example, if there are 7 intervals in the AvailableIntervals list, the domain of the available inversions is 1..12.
  By default, the first value in this list is used, but if the chord’s OrnamentData field is set, the inversion number is set to
  
  AvailableInversions[OrnamentData.intList[OrnamentData.pValue]].
  The number of available inversions in the AvailableInversions list must therefore be greater than or equal to the domain of the OrnamentData.intList.
  
• Input pin 4: (string) AvailableIntervals. A string of comma-separated integers in the range 1..127. These are the intervals which can occur between neighbouring notes in the output chord.
  The number of available intervals in the AvailableIntervals list must be at least (maxDensity - 1), where maxDensity is the maximum value in the AvailableDensities list. For example, if the maximum density is 7, there must be (at least) 6 intervals in this list.
  
• Input pin 5: (string) AvailableVelocityCurves. A string of comma-separated floating point values in the range 0.0..10.0. The velocity of the top pitch in the chord is equal to the velocity of the bottom pitch multiplied
  by this factor. The velocities of intervening pitches are geometrically interpolated. In effect, this is a way of controlling
  the chord's brightness.
  By default, the first value in this list is used, but if the chord’s OrnamentData field is set, the velocity curve is set to
  
  AvailableVelocityCurves[OrnamentData.intList[OrnamentData.pValue]].
  The number of available velocity curves in the AvailableVelocityCurves list must therefore be greater than or equal to the domain of the OrnamentData.intList.

Algorithm: The values in the AvailableIntervals list are used, in the order they occur in the list, as the labels of a linear krystal field. This field has 2*(N-1) distinct areas, numbered from 1..(2*(N-1)). These are the 'inversion' numbers.
See Study 1. The hierarchy in each inversion area determines the order in which the intervals are added to the top of the chord. So, to determine the notes in a chord:

1. determine the chord’s density (see input pin 2 above)
2. determine the chord’s inversion number (see input pin 3 above)
3. populate the linear field with the available intervals (input pin 4)
4. using the field and inversion number, find the order in which to add intervals
5. add as many notes as necessary to the chord, by adding intervals in the now known order to the top of the chord, starting with the existing note as root, and calculating the velocity according to the value in Input pin 5.

Example patch: Adding a SetChordNotes node to the above krystalStreamOrnament patch just above the MIDI OUT node (and changing the file name displayed on the MIDI OUT node), gives the following patch:


See xk4(7.7.1)-1.kexp content above.
1. a version produced by sending a middle C irregularly (by hand) to the patch, waiting for each ornament to complete. 2. a version with overlapping ornaments. The pitch sent by hand changes.

• Input pin 1: (MidiStream) Receives MidiStream messages. If an incoming ChordOn message has its OrnamentData set, this node sends a MIDI Pan message before relaying the ChordOn message to the output pin. Other MIDI messages arriving at Input pin 1 are relayed unchanged.
  
• Input pin 2: (string) AvailablePanSettings. A string of comma-separated floating values in the range 0.0 to 100.0. A value of 0.0 sets the pan to extreme left, 50.0 is centre, 100.0 is extreme right. By default, the first value in this list is used, but if the chord is part of an Ornament (it contains an OrnamentIndexList and an index in that list), the Pan value is set to
  
  AvailablePanSettings[OrnamentData.intList[OrnamentData.pValue]].
  The number of available pan settings in the AvailablePanSettings list must therefore be greater than or equal to the domain of the OrnamentData.intList.

Example patch: Adding a SetChordPan node to the above krystalStreamOrnament patch just above the MIDI OUT node (and changing the file name displayed on the MIDI OUT node), gives the following patch:


See xk4(7.7.1)-1.kexp content above.
In the following two examples, the dynamic (velocity) of each ornament was deliberately controlled (live) using the keyboard.
1. a version produced by sending a middle C irregularly (by hand) to the patch, waiting for each ornament to complete. 2. a version with overlapping ornaments. The single pitch sent by hand changes.

If an incoming ChordOn message has its OrnamentData set, this node sends MIDI messages to set the pitch wheel before relaying the ChordOn message to the output pin. The pitch wheel's range and setting are both set. Other MIDI messages arriving at Input pin 1 are relayed unchanged. Input pin 2 need not be connected. If it is not connected, it has a default value of 2.

• Input pin 1: (MidiStream) A stream of MidiStream messages.
  
• Input pin 2: (float) The maximum number of semitones by which the pitch wheel can transpose pitches up or down. This pin need not be connected for the node to run. If it is not connected, it has a default value of 2.
  
• Input pin 3: (string) AvailablePitchWheelSettings. A string of comma-separated floating point values in the range 0..100. A value of 0.0 transposes the chord down by the number of semitones set in input pin 2. A value of 50.0 renders the pitch at its normal value, and a value of 100.0 transposes the chord up by the number of semitones set in input pin 1. By default, the first value in this list is used, but if the chord’s OrnamentData field is set, the PitchWheel is set to
  
  AvailablePitchWheelSettings[OrnamentData.intList[OrnamentData.pValue]].
  The number of available pitch wheel settings in the AvailablePitchWheelSettings list must therefore be greater than or equal to the domain of the OrnamentData.intList.

Example patch 1:
Adding a Set Chord PitchWheel node to the above krystalStreamOrnament patch just above the MIDI OUT node (and changing the file name displayed on the MIDI OUT node), gives the following patch:


See xk4(7.7.1)-1.kexp content above.
1. a version produced by sending a middle C irregularly (by hand) to the patch, waiting for each ornament to complete. 2. a version with overlapping ornaments. The single pitch sent by hand changes. 3. a version with overlapping ornaments, using differing major triads as the seed.
Example patch 2:
To demonstrate using this node to produce small pitch changes, here is the same patch with the following changes:

1. The Ornament node’s Available chord transpositions have been changed to (0,0,0,0,0,0,0), so that each ornament consists of repetitions of the same pitch.
2. For the Set Chord PitchWheel node, the deviation has been changed to 1 semitone (the minimum value).
3. The available PitchWheel settings have been changed to (0, 8.2, 14.1, 20, 32.9, 40.55, 50) — which are fairly random floating point values in the range 0..50).

With this setup, a value of 1 in the original krystal will be performed at a pitch 1 semitone lower than the performed pitch. A value of 7 will be performed at the original pitch.
MIDI theoretically supports transposition differences as small as 1 cent (1/100 semitones). With a pitch wheel deviation of 1 semitone, a 1 cent pitch difference would be created using a difference of 0.5 in the available PitchWheel settings. However, there is not much point in setting the available PitchWheel settings to (0, 0.5, 1.0, 1.5, 2.0, 2.5), since 1 cent pitch differences are below the limit of audibility... (I cant hear them, anyway!)


See xk4(7.7.1)-1.kexp content above.
This version was produced by sending a middle C irregularly (by hand) to the patch, waiting for each ornament to complete.

• Input pin 1: (MidiStream) Receives MidiStream messages. If an incoming ChordOn message has its OrnamentData set, this node sets the chord’s velocity (loudness) according to the node’s parameters (see below). Other MIDI messages arriving at Input pin 1 are relayed unchanged.
• Input pin 2: (string) An optional string of AvailableOrnamentEnvelopes.
  If this pin is not connected to a string node, each chord’s velocity is simply set using a factor retrieved from input pin 3.
  If present, the AvailableOrnamentEnvelopes is a string of colon-separated envelope descriptions. Each envelope description is a string of comma-separated decimals in the range 0.0 to 10.0. The decimal point, which is optional, is the ‘.’ character. White space can be used ad lib. Inside an envelope definition, there are an unlimited number of values, and values may repeat. For example:
  
         10,0 : 5.6,10,5 : 2,10,9,5.3,1 : 6 : 5,5,10 : 5,10 : 10
  The ornament’s pValue is used to select one of the envelopes from the list.
  AvailableOrnamentEnvelopes[OrnamentData.pValue].
  So the number of envelope definitions in the AvailableOrnamentEnvelopes list must be greater than or equal to the domain of the OrnamentData.pValue.
  
• Input pin 3: (string) AvailableVelocities. A string of comma-separated decimals in the range 0.0 to 10.0.
  The decimal point, which is optional, is the ‘.’ character.
  White space can be used ad lib. For example:
         10.0, 5.6, 7.5, 6, 5, 4, 2
  These numbers, divided by 10, are the factors by which the incoming chord’s velocity is multiplied.
  
  AvailableVelocities[OrnamentData.intList[OrnamentData.pValue]].
  The number of velocity factors in the AvailableVelocities list must be greater than or equal to the domain of the OrnamentData.intList.
  If Input pin 2 is set, the velocity will be multiplied again using an envelope factor (see above).

Algorithm: Each chord’s velocity is first set using a factor from input pin 3, then multiplied by a factor calculated from the envelope data as follows:
The values in the envelope string are first divided by 10. The factor for the first and last chords are the first and last factors in the envelope respectively. Other factors are calculated by distributing the other values in the envelope uniformly (by chord number) across the ornament, and interpolating a factor for each chord.
If the ornament has only one chord, the first envelope factor is used.
If the ornament has two chords, the first and last envelope factors are used.
If the envelope only has one factor, that factor is used for all the chords in the ornament.

Example patch: Adding a SetChordPitchwheel node to the above krystalStreamOrnament patch just above the MIDI OUT node (and changing the file name displayed on the MIDI OUT node), gives the following patch:


See xk4(7.7.1)-1.kexp content above.
First, three examples in which the AvailableEnvelopes input has been detached from the Set Chord Velocity node:
1. a constant middle C was sent irregularly (by hand) to the patch, waiting for each ornament to complete. 2. a version with overlapping ornaments. The pitch sent by hand changes. 3. a version with overlapping ornaments, using differing major triads as the seed.
Now three examples in which the AvailableEnvelopes input has been re-attached to the Set Chord Velocity node. The ornaments now have superimposed velocity envelopes.
Note that the envelope shapes are chosen by pValue (see xk4(7.7.1)-1.kexp ).
4. a constant middle C was sent irregularly (by hand) to the patch, waiting for each ornament to complete. 5. a version with overlapping ornaments. The pitch sent by hand changes. 6. a version with overlapping ornaments, using differing major triads as the seed.