BTDSys PeerChord

Installation

Put BTDSys PeerChord.dll in your Gear\Generators folder.

Overview

PeerChord is a chord/arpeggio player, which can control any other machine in Buzz (provided the machine supports notes and tracks). Also facilities for 'humanisation' (simulating a human player) are provided.
This is the full version of PeerChord, giving you fine control over all aspects of your chords and arpeggios. If you do not need such flexibility and want a simpler machine to use, try the Lite version.

• Add PeerChord to your song.
• You don't need to connect any other machines to PeerChord.
• Right click PeerChord and select Assign Parameter, then click an unassigned track.
• In this dialog, choose the machine you want to control, and either a note parameter, velocity parameter, or both.
• Click OK.
• Add at least six tracks to the target machine.
• Add a pattern to PeerChord, playing notes.
• If you want to control more than one parameter from the same PeerChord, add more tracks to the machine (Pattern view, Ctrl +). Then assign them as above.

Parameters

• Root - sets the root note (lowest note) of the chord.
• Chord Type - sets the type of chord to use. None plays single notes, and Custom allows you to define your own chord using the Custom parameters. For a list of chords and their numbers, right-click the machine and choose About.
• Velocity - the velocity (volume level) of the chord.
• Random Velocity Deviation - sets how far from the set velocity the notes may stray at random (to simulate the slight variations in velocity of a human player).
• Delay Mode - Sets the mode used for delaying.
  • Off triggers all notes immediately
  • Simple delays all notes by a set amount
  • Random delays all notes by different random amounts (as if a keyboardist did not hit all notes at precisely the same time)
  • Strum modes simulate a guitarist's strum down or up the strings.
  Note that these modes are overridden if any arpeggio mode is set.
• Delay Length - Depending on the Delay Mode used, either sets the time to delay notes by (simple), the maximum of the random delay (random), or the time between consecutive notes (strum).
• Note Cut - Sets how long notes are sustained (they are stopped by sending note offs). Note that the target machine may cut notes off earlier; try adjusting the other machine's envelope settings if this is the case. If this is set to Infinite, then PeerChord will not attempt to cut notes.
• Arpeggio Mode - Sets the type of arpeggio to use.
  • Off plays a simple chord (all notes at once)
  • Up and Down simply loop up or down the notes in the chord.
  • Up/Down and Down/Up swap directions when the first or last note in the chord is reached.
  • Random chooses notes from the chord at random.
  • 'Brownian' selects the next note based on the previous note. The next note will either be one step higher, one step lower, or the same as the previous note.
• Arpeggio Steps - Sets the number of notes to use for the arpeggio. If this is more than the number of notes in the chord, octaves of the notes are used to obtain the required number of notes.
  Note that this is not necessarily the same as the time taken for one complete cycle of the arpeggio. It is for up and down modes, but for up/down and down/up the length of a complete cycle is actually 2 × (Arpeggio Steps - 1).
• Arpeggio Step Length - Specifies the duration between consecutive steps of the apreggio.
• Arpeggio Reset - Sets if the arpeggio is reset to its start point every time a new note is played (this applies both to tracked notes and MIDI notes). Note that if no note is currently playing (ie if a note off was played or you lifted your finger from the MIDI key) the arpeggio is reset anyway.
• Arpeggio Hold - Allows arpeggio playback to be temporarily halted. A value of 1 will keep triggering the current note over and over, while a value of 2 will stop note triggering altogether. A value of 0 will resume arpeggio playback where it left off.
• Arpeggio Shuffle Step - Every nth arpeggio note will be delayed by some amount, where n is the value of this parameter. A value of 0 (off) will prevent any notes from being delayed.
• Arpeggio Shuffle Length - The amount every nth note is delayed by.
• Arpeggio Shuffle Reset - A value of 1 resets the shuffle counter to 0 (the counter which counts up to every nth note).
• Octave R,2 / 3,4 / 5,6 - Allow you to use alternate voicings and inversions, by setting the octave each note of the chord lies in (as offsets from the default octave). The parameters are "doubled up", meaning the first (most significant) hexadecimal digit sets the offset for the first note, and the second digit for the second note. So a value of 0x88 specifies the default octave settings (+0, +0), 0x87 specifies (+0, -1), 0x6A = (-2,+2), etc etc.
• First Track - This sets the first track of the target machine to use. At most 6 tracks will be used, so if you set this to 2 (for example), you should ensure tracks 2, 3, 4, 5, 6 and 7 are available on the target machine.
• Custom Notes 2-6 - Sets the notes used for the custom chord (if the Chord Type parameter is set to Custom). A chord always contains its root note, and up to 5 other notes above the root. These parameters set the offsets (in semitones) of these notes.
  It is normal to specify these notes in ascending order (lowest to highest), but if you are aiming for special effects with the strum or arpeggio modes, you may use a different order.

Attributes

• MIDI channel - the MIDI channel the machine listens to, or 0 disables MIDI functionality.
• MIDI track - the track on the PeerChord machine which receives the MIDI notes.
• MIDI transpose - allows incoming MIDI data to be transposed up or down by upto 2 octaves. Note that a value of 24 represents no transposition, 0 represents down 24 semitones (2 octaves), and 48 represents up 2 octaves.
• MIDI velocity - if this is set to 1, the Velocity of the chord is taken from the velocity of the MIDI key pressed. If it is set to 0, the value of the Velocity parameter is used.
• MIDI snap to tick - specifies whether chords are triggered immediately (0), or on the next tick (1). If Arpeggio mode is active, the arpeggio is always triggered on the next tick.
• Velocity compensation - Lowers the note volumes when a chord with more than one note is played. A value of 0 gives no compensation, while a value of 1024 gives maximum compensation (so notes in a 2-note chord are ¹/₂ the normal velocity, notes in a 3-note chord are ¹/₃ the normal velocity, etc). Values between 0 and 1024 are between the two extremes. This applies to both chords played through patterns, and through MIDI (although not to arpeggios).

All but one of the attributes relate to MIDI functionality. If you play a note on a MIDI keyboard, PeerChord will play the current chord type with the MIDI note as root note, and with whatever delay/arpeggio settings are specified. Note that MIDI support on PeerChord is monophonic, ie only the most recently played note is used.

Other notes

• If the PeerChord machine is muted, either directly or by soloing another machine, it may cease to function properly until it is unmuted again.
• PeerChord uses hack methods to trigger notes at times other than on the tick. However, it is possible that this could cause problems with some machines or with future versions of Buzz. Also the Record function in Buzz will not record all of PeerChord's parameter changes into the target machine's patterns.
  If you wish to disable the hack methods, please ensure:
  • Delay Mode is set to Off
  • Arpeggio Step Length represents a whole number of ticks.
  • MIDI snap to tick is set to 1 (on)
  • Note Cut is set to Infinite.

Contact

If you have comments or suggestions, or if you find any bugs please email me.
This machine is DONATIONWARE, so if you like it, send me something cool (eg CDs, hardware, money etc). Email for details of how to get stuff to me.
Also visit my website (y'know, if you're bored).

Thanks to everyone who alpha tested this machine for me and suggested features/pointed out bugs - particularly Ra·l Reales (who gave me the original idea), Cameron Bonde (Vectrex), Juri Puumala, K.M. Krebs, Jeph Wacheski, Ronny Pries, and whoever else I forgot.

Docs and code ⌐Ed Powley (BTDSys), July/August 2002