HarpTime VST synthesizer for Windows and AU for Mac

copyright NUSofting 2003 - 2009

 

Documentation written by Luigi Felici (Liqih), with editing by Sean Ahern.

Introduction

The HarpTime VST synthesizer was designed to reproduce the sound of the plucked folk harp, and uses an advanced physical modeling synthesis in which twelve strings are all individually modeled to allow true sympathetic resonances.

HarpTime can reproduce the beautiful sound of the Celtic harp, as well as that of many similar types, such as Japanese (the koto), Paraguayan and African harps.

(See the "Selected Links" appendix, at the end of this document, for more information about harps, including references on types, playing methods, and harp music).

HarpTime is available in two versions, the fully-featured 'Pro' version, and a simpler 'Fun' version which is more immediate to use.

The 'Fun' version features less polyphony and less parameter controls than the 'Pro' version, but presets are compatible between both versions.

You may be unsure if you need a harp synthesizer. Or perhaps you have never used VST plugins before. To help you, we have compiled a HarpTime FAQ.

Currently, the HarpTime VST synthesizer is only available for PC's running Windows (System Requirements are listed in this document before the appendices).

Features Overview

Let's quickly overview the powerful features of this unique synthesizer:

String Modeling

HarpTime features a sophisticated sympathetic resonance among a set of 12 individual physically-modeled strings. Furthermore, in the 'Pro' model, each string is simulated with its own timbre and pluck position parameters, for a more realistic acoustic emulation.

Additionally, the strings can be tuned individually, which allows the use of microtuned intonations and scales.

The maximum polyphony is 12 simultaneous voices for the 'Pro' model and 8 voices for the 'Fun' model.

Bray Pins

Another unique feature of this synthesizer is its modeling of the effects of a harp's Bray Pins (which hold a string to the body of the harp) There are ten different different attack and decay behaviors modeled, by means of a "Shaping" control, some of which model the classic buzzing tone of mediaeval harps.(See later for an explanation of Bray Pins)

Performance Features

A unique "SelfBend" feature is implemented to emulate the pitch envelope typical of loose strings.

In addition, there is an adjustable smoothed Pitch Modulation, controlled by an LFO.

The playing style (from soft to hard plucking) can be affected by a "Pick" control which allows variation in the touch of the player.

Velocity Sensitivity is adjustable

A "Damp" switch allows the sustain of HarpTime's strings to be set on HarpTime's control panel; this control behaves similarly to the Release stage of an amplitude envelope on a more typical synthesizer

The master tuning frequency of the synthesizer can also be adjusted.

The ModWheel can be used to 'strum' octaves, in a Glissandi effect. Only the white notes are played.

Effects

A double "Low Pass/Band Pass" filter, which allows a great deal of control over the timbre of the sound. This means, for example, that electric harp timbres are possible.

The internal stereo Chorus adds more depth and timbral variation to the sound.

Controls

String Controls

The following controls are implemented as a single set in the Fun version, or one separate set per string in the Pro version of HarpTime.

- "Exciter" (per string) Controls the maximum energy sent to the string

- "Tuning" (per string) Retunes the string range -100 to +100 cents of semitone

- "PikPosi" (per string) Controls the effective pluck position on the string, changing the harmonics of the sound

- "PikBrig" (per string) NoiseFilter Frequency Control affects brightness of picking,

In the Pro version the controls for the "C" string act as the 'master' setting which can be applied to all the strings. For each string there is also a "Link" switch, which slaves that string "s settings to the master settings. Each string may be individually slaved or independent. If the "Link" switch for the "C" string is off, all controls are independent of the master settings regardless of their own Link button
state.

Global Controls

The following controls affect all strings :

- "Modulation" : Controls the amount of pitch modulation. This also enhances the sympathetic resonance.

- "PickAtak" : Controls the effective strength of the string pluck. This affects the tone and dynamics.

- "SelfBend" : Affects the modeling of loose strings. This may be off, or control how loose the strings are.

- "Sympathetic" : Controls the amount of sympathetic resonance. This may be turned off completely.

- "Damp" : Allows control over the volume decay of strings. This may be switched off (allowing a natural decay), or a specific decay time may be set.

- "Shaping" : Sets the attack and decay behavior of the strings, the Bray Pins model used and the strings type.

- "DynaTone" : This controls the emphasis/frequency ratio of the filter, or switches it off.

- "ToneBals" : This controls tone balance of a simple low-high tone EQ filter (left = low, right = high)

- "Velocity" : Controls the sensitivity to MIDI Velocity

- "Pitch" : Allows retuning of the master pitch of the whole synthesizer

- "Chorus" : Controls the amount of chorus effect applied, or switches it off.

- "Volume" : Controls the output level of the synthesizer

- every knob is controllable by VST automation. In addition, HarpTime responds to five different MIDI CC values:

Note that the MIDI CC response for these controls (for values of 0..127) is scaled to the maximum set by the actual parameter setting. Hence if a parameter was set to a value of 100, a MIDI CC value of 0 would be equivalent to an 'active' parameter value of 0, a MIDI CC value of 64 would be equivalent to an 'active' parameter value of slightly over 50 (64/127), and a MIDI CC value of 127 would be equivalent to an 'active' parameter value of 100.

- GUI Customization - You can change the decorations on the corners of GUI panels, by clicking on them. The chosen look will be remembered for the next time you open the instrument.

Parameters interaction explained

An explanation of how the various controls of HarpTime interact to tailor the final sound.

Interaction of the Exciter, Pick, SelfBend and Shaping controls

The Exciter control can be viewed as determining how hard and far the harp string is pulled when it is plucked. This has a strong effect on the SelfBend amount (thus varying the pitch envelope) and also on some Shaping settings, mostly those which change the attack.

Low Exciter setting usually leads to a more realistic sound.

Note : When PickAtak (the level of Pick excitation) or PikBrig is set to zero (ie hard left), the attack on low notes may produce an unnatural click. To avoid unrealistic pluck sounds, PickAtak and PikBrig should not be set to zero.

Interaction of the Exciter, Pick and Velocity controls

PikBrig and PickAtak are more velocity-sensitive than Exciter values.

Interaction of the Tuning and Pitch controls for "metallic" sounds

The interpolation algorithm used to tune the synth engine is frequency-dependent. This may mean that some notes may sound more metallic than others. This can be compensated for by changing note pitches, either individually (Tuning control) or globally (Pitch control).

This is different when using Shaping setting 11 (all LEDs on) since a different interpolation method is used. Shaping setting 11 exhibits a more natural metallic sound across the whole range.

Modulation and Sympathetic

When the Modulation control is set to high values, the Sympathetic control settings are adjusted to allow more resonance. This prevents unmodulated resonances which may result in unwanted feedback sounds.

Note also that the Sympathetic resonance control is not muted by the Damp control.

Dynatone and ToneBals

When the Dynatone filter control has a high settings, this will also increases the volume, like a "boost" effect .

The ToneBals control is active ONLY when the Dynatone filter is on.

Together, Dynatone and ToneBals can be used to emulate an electric harp with pickups. Adjusting PikPosi will help this type of emulation.

Important Things to Remember

System Requirements

Minimal: 500 MHz MMX™ CPU with Windows® 98, ME, NT 4.0, 2000, or XP 64 MB RAM and high-quality sound card.

Screen settings: 800x600, high colors (16 bit).

Suggested: 2000 MHz (the faster the better) MMX™ CPU with Windows® XP, 256 MB RAM,

Screen settings: 1024x768, true colors (32 bit),

Note : An ASIO soundcard is recommended for low latency real-time play.

     
     
 
Appendix 1: Frequently Asked Questions
Questions:
  1. Do I need a harp synthesizer?
  2. Do I need to install a sequencer program to be able to use HarpTime?
  3. Why is HarpTime a VST plugin rather than a standalone program?
  4. What is better: a harp sample library or HarpTime VSTi?
  5. What are the differences between the Pro and the Fun version?
  6. Does HarpTime support microtuning?
  7. Why is tuning per note so important in HarpTime?
  8. How does the polyphony work in HarpTime?
  9. How do I play or program realistic harp parts?
  10. Which features might appear in the next version?
  11. What is the CPU usage like?
  12. What are "Bray Pins ", and how do they affect the sound of HarpTime?

Answers

  1. Do I need a harp synthesizer?
  2. Maybe. The harp has a beautiful sound which is usable in very many musical styles (mediaeval period music, classical, ambient, film music and ballads, for example).

    However, samples can only reproduce a limited, and somewhat 'static' snapshot of a particular real instrument being played.

    In comparison, physical modeling allowed us to build a VSTi which reproduces the characteristic of a variety of real harps, with more flexibility, control, and dynamics than a sample set will normally provide.

    Using HarpTime, anybody with a PC and a MIDI keyboard can enjoy playing a good sounding virtual harp.

  3. Do I need to install a sequencer program to be able to use HarpTime?
  4. No. HarpTime comes complete with a free small 'host' program which means that all you need is a soundcard, and some kind of MIDI keyboard. This can be a real keyboard, which is recommended if you wish to be able to play dynamically (louder or softer notes etc..) or you can use a 'virtual keyboard' program which you control with your PC's mouse and keyboard. (For 'virtual keyboard' software, you can search http://www.whiterabbitdesign.co.uk/stuff/docs/www.google.com for GMKbd or Bomes Mouse Keyboard)

    Tip: the program "Chainer" is a very small, full featured host, which very easy to use and it also lets you play directly from the PC keyboard. An almost fully-featured demo version is available at http://xlutop.com/html/downloads.html

    Forte Solo is another, similar freeware host and can be found at http://www.brainspawn.com/

    (Note : The included mini-host, and the other two hosts mentioned above are only suitable for playing 'live'. To write record and write music in MIDI format you need

    a VST2 host with sequencer, as mentioned in the next question)

  5. Why is HarpTime a VST plugin rather than a standalone program?
  6. The VST plugin standard allows HarpTime to be used within a variety of compatible software packages (called 'hosts' or 'VST hosts'), at the user's choice. This is much more flexible than standalone software.

    An amazingly wide range of programs are available which can host plugins like HarpTime. These range from basic freeware packages, to expensive fully-featured professional-class software.

    There are effectively three 'types' of VST hosts which you can use to control HarpTime:

    • with MIDI input only (like the one included with HarpTime)
    • with internal sequencing only (mostly free programs, called 'trackers')
    • with full MIDI input, recording, and sequencing (such as Cubase, Logic, Sonar, Orion etc...).

    A sequencer allows you to write music which can be saved, and replayed. A Sequencer with MIDI input allow you to record notes in real time as you play, then edit, save and replay them.

    For more info about available sequencers visit http://kvr-vst.com/

  7. What is better: a harp sample library or HarpTime VSTi?
  8. This actually depends on your needs. But we think that HarpTime has several significant advantages.

    • Flexibility - Because the HarpTime sound is generated in 'real time', and the model features a variety of parameters which directly affect that sound, many variations of the harp can be simulated.
    • Complexity of Sound - Samples are static snapshots of a particular instrument in a particular place, played a particular way. Using velocity layers and software modulation you can 'animate' the sound somewhat, but the variation would still be something dependent on what was recorded. For a physical model such as HarpTime, every note is a new acoustic event, created in real time, just like it would be in a genuine wood and strings instrument. Moreover in HarpTime many factors interact, resonate and intermodulate with each other, producing a sound which is far more complex and detailed, just like in a real harp. The sum is much more than the parts.
    • Price: Quality sample libraries can be expensive, and you would also need a software sampler to play them, which could cost a large amount of money as well. HarpTime can be bought for a tiny fraction of those costs.
    • Size: HarpTime doesn't use samples, so uses very little memory and space on your hard drive, almost nothing when compared to a quality sample library.

    However we must admit sample libraries have the advantage of Low CPU usage - Very little computation power is needed to crossfade and play samples.

    One other area where sample libraries currently have an advantage is in recreating the classical concert harp. The full, long ringing tone of a big pedal harp is technically possible to model, but its computation cost would be far too heavy, so this has not been implemented in HarpTime. A high-quality sample library would currently be a much better alternative. However, it is possible that the HarpTime engine will be capable of modeling the concert harp in future.

  9. What are the differences between the Pro and the Fun version?

    • Polyphony - 'Pro' version has 12 voices, 'Fun' version only has 8
    • Pro version sounds a bit fuller than Fun
    • Pro has per-string controls for "Exciter","Tuning" ,"PikPosi","PikBrig"
    • The CPU usage is about 20% higher in the Pro version
    • Presets can be exchanged between the two versions

  10. Does HarpTime support microtuning?
  11. Yes. Each of the 12 notes can be transposed up to 100 cents up or down.

    This allows "just intonation" for perfect modal playing, as well as the creation of several diatonic modes.

    For example you can tune E and A to -100 cents, so the scale played on on the white keys becomes C D Eb F G Ab B, which is C minor. This way you can make glissati in minor keys easier.

  12. Why is tuning per note important in HarpTime?
  13. This feature is only supported in the Pro version of HarpTime.

    The range of each tuning control (12 knobs) is -100..+100 cents (+1..-1 semitone).

    Small offsets from the standard tuning help to get the best resonance relative to the tonality (musical key) played. For example if one is playing in C Major, retuning E and G will give you the perfect consonance for many harmonics of the notes of the C major scale, and thus a richer resonance for the harp sound.

    Big offsets of 1 semitone let you modify the mode of the scale. This can be useful in two cases:

    1. When you recorded a MIDI part in one mode (e.g. C Major C D E F G A B) and you wish to play it in another one (e.g. C Db E F G AB Bb, which would require that D, A and B were each detuned down 1 semitone).
    2. When you want to make it easier to play easy a part on the white keys (e.g. glissandi) but the scale would normally use some of the black keys. (e.g. tune the scale to C dB Eb F Gb A Bb to have a diminished glissando on white keys)
  14. How does the polyphony work in HarpTime?
  15. HarpTime is fixed at 12 voices of polyphony. This cannot be reduced since each of the 12 voices corresponds to a string which contributes to the sympathetic resonance of the harp as a whole. This resonance is always active, so even if only one string is plucked, all twelve 'strings' are made to vibrate. Thus the load on the CPU is constant, no matter how many of the twelve voices are being used for plucked notes.

    By turning on the 'Damp' control, you can change the model so that only the strings actually played by MIDI will resonate, which will reduce CPU usage if you play only a few notes, but this also reduces the accuracy of the harp model. This reduces the number of active voices, but not the total polyphony.

  16. How do I play or program realistic harp parts?
    • Arpeggiate! It may seem obvious, but playing arpeggio is an intrinsic part of the technique of a harpist..
    • Strum softly, avoiding cluster chords.
    • Use glissando. This performance 'motif' is probably most familiar from classical harp music; it is not used much in folk harp music.
    • Don't quantize too perfectly, or to precise time-divisions. The timing of playing a harp is always oscillating: a bit faster, a bit slower.
    • Avoid repeating the same note consecutively too many times - this will result in an unwanted percussive effect.
    • Use a wide velocity range. Alternate weaker notes with stronger notes.
    • Listen to real harp tracks.
  17. Which features might appear in the next version?
  18. HarpTime is in constant development. Many suggestions for the future already been made, such as extending the number of scales available from the Automated Glissandi feature (controlled by the ModWheel ).

    We are also working on optimization of the CPU load, and a richer resonance model.

    An arpeggiator designed to simulate typical harp playing styles is another possibility.

  19. What is the CPU usage like?
  20. A distinct aspect of the harp's sound is the rich resonance caused by the interactions of the large number of freely vibrating strings. This requires much more computational power than many 'normal' synthesizers... HarpTime performs real-time simulation of 12 interdependent vibrating strings using 36 delay lines all at the same time. This is much more complex than a single separate resonator like a reverberation effect, because the sympathetic resonance of HarpTime is constantly changed by the strings actually playing - it changes realistically as part of the performance.

    As a guide,

    On a Pentium III running at 1400 Mhz, the maximum CPU usage is 30%.

    On a Pentium 4 running at 2530 MHz the maximum CPU usage is 21%.

  21. What are "Bray Pins ", and how do they affect the sound of HarpTime
  22. Many harps in 15th century paintings had bray pins, which served the double function of holding the string to the soundboard and could also be turned and delicately positioned to touch the strings in such a way that a buzzing, humming sound resulted. The bray pins both changed the timbre and increased the volume of the sound produced, so that the gothic harps with very slender bodies and thin, small soundboxes had a tone capable of good projection in appropriate acoustics.

    http://www.harpspectrum.org/historical/fulton_short.shtml

    bray harp: Medieval and Renaissance harps which use "bray pins", adjusted to lightly touch each string to create a loud buzzing tone. Bray pins are usually L-shaped, can be moved away from the string for a "regular" tone, and have the additional function of attaching the string to the soundboard.

    http://www.harpspectrum.org/glossary/glossary.shtml#bray

 

 

 

Appendix 2: Selected Links

The Magic and Ease of the Harp. Read about harp coolness : http://traditionalharps.com/HarpsGeneralEasy.html

Types Of Harps : http://members.aol.com/tonymorosc/harppage/harp3.htm

HARP PARTS: http://traditionalharps.com/HarpsGeneralParts.html

Folk Harp : http://www.harpspectrum.org/folk/folk.shtml

Other Harps ­ All Harps Bright and Beautiful : http://traditionalharps.com/HarpsGeneralOtherHarps.html

Traditional Welsh Harp Technique and Middle-earth Music : http://www.elvenminstrel.com/tolkien/welshharp.htm

Laurie Riley - Music Heals: Music for Healing and Transition http://traditionalharps.com/HarpsLaurieRileyHealing.html