John Valentine
Surge: Solo Violin

The Solo Violin patch is included with the Surge XT plug-in that you use with your DAW or play standalone. It synthesizes the sound, with physical modelling, and modulations that mimic playing mechanics. I update it from time to time, and might tweak the design to suit a given performance.

Nothing beats a live performance by a virtuoso. This guide provides hints for a non-player (or even a player), a composer, or music writer, to approach some of the sound possible with a real violin, and articulate versatile performances without needing a huge sample library and several virtual instrument tracks.



Demo 1: Surge Storm

The violin plays the solos in the first part, and the string sections in the remaining parts. It shows how the instrument resonates when pushed with expression, and shows the dynamic range of the instrument without needing gain automation. The cellos and basses are are derived from this violin.

Demo 2: Massenet's Meditation from Thaïs

Typically a grade 7 or 8 piece for solo violin, this demonstrates most of the controllers of the Violin 2021 patch. It also uses Grand Piano 2021 and Cello 2021, but Violin 2021 is given prominence.

Controller summary

This patch simulates a string using the Karplus-Strong algorithm, excited by a bow, and supported by body resonances typical of a solo violin. It's responsive to the macro controllers that define the characteristics and expressions of the violin:

MacroMIDI CCNameDescription
141Bow speedAffects how often the bow slips and grips the string. Use a slow speed, along with Grit and Bow direction to add detail to the bowing action.
242Bow forceSet above zero to make a sound. 60% is good for a resonant note without introducing inharmonic sounds.
343Bridge muteDampens the sound. The lowest setting is unnaturally rich in high frequencies, but you might want to use this effect creatively.
444Bow directionExperimental: changes the tone of the sound.
545Finger vibratoManually modulate the pitch of the note, which also slightly affects the loudness of the sound
646Open stringExperimental: allows the note to resonate without finger damping.
747GritAdds the scraping sound of the bow before it settles into an even excitation of the string. Use for changes of bow direction or aggressive bowing.
848ReverbControls closeness and room ambience.

Typically, you'd configure and macros Bridge mute and Reverb once at the start of a performance, and adjust the others during the performance.

Basic configuration and playing hints

  1. The important controllers are Bow force and Finger vibrato. Introduce more emotion with Pitch bend, and embellish with playing mechanics with the other controllers.
  2. Use Vibrato for simple vibrato, or use Finger vibrato to modulate the pitch explicitly. Increase the modulation of pitch, if the current setting does not offer a wide enough vibrato range (around 0.3 semitones, a typical maximum for solo playing).
  3. Increase OSC1: Excitation to introduce the 'hollow body' inharmonic noise of very slow and gentle bowing.
  4. Use Pitch bend to slide between notes. Usual violin playing hints apply when doing this: reduce Bow speed and Bow force as required, if you don't want glissando to be prominent.
  5. Introduce Grit when changing bow direction or landing the bow on the string. This resonates through the bridge and body to give the characteristic mechanical noises that you hear during energetic solo performances.
  6. The FX section is configured for A (air), B (body), and a couple of other resonances of a violin. You can change these to give your violin the characteristics of a preferred orchestral violin or solo violin.

Set up the virtual violin

Tuning and pitch controls

Just like other Surge instruments, you can choose from the Surge tuning presets, load custom tuning, or change the reference pitch of the instrument. Alternatively, you can play occasional notes off-scale using Fingered vibrato or Pitch bend. Set your Pitch bend range to suit the range of your performance or preferred calibration scale.

String tension

You can change the string tension of OSC1 directly, but this might adversely affect the character of the instrument. Also, outside the sweet spot in the middle of the Tension parameter, tuning maps disproportionally.

Resonance profile

The body resonances are configured to be similar to those researched as 'ideal'. However, you might want to tweak them to suit period or character of your instrument. The FX section is configured for A (air), B (body), and a couple of other resonances of a violin. You can change these to give your violin the characteristics of a preferred orchestral violin or solo violin.

For example, if you want to increase the mass of your fingerboard, by sticking virtual sticky-tack to the underside, then you can achieve the same by reducing the frequency of the RES (resonance) and EQ (spectral compensation) components that are around 118Hz.

Likewise, you can change the post, body and airspace by tweaking the others. There's lots of good research out there, for values you might like to use. We've captured about nine of them explicitly in this instrument, and some more complex profiles are given by the AW FX units.

Bridge mute

Set the Bridge mute macro high to dampen the higher harmonics of the strings. You can do this in real-time with this instrument, to the level required.

Basic expression

Bow force (CC42)

When you start a note with your MIDI controller, you'll hear silence if Bow force is set to zero. This patch needs you to control the Bow force. As a first approximation, you might want to set this macro to around 60%, and hear what that's like.

Hint: If you're using a keyboard with a modulation wheel, you might like to map that to use the same modulations as Bow force, using Copy targets on Bow force then Paste on Modwheel.

Next, you'll want to draw in (or record, through a controller) Bow force as the note plays. Start at 40% or higher. To make a loud sound, it takes a bit of force to begin with, along with Bow speed and you can then greatly vary the Bow force. Because the instrument 'rings' with the resonance, you might find small changes of Bow force take time to change the loudness of the sound.

Ideally, you'll not need to automate the output levels of the instrument in the DAW, because the instrument has a wide dynamic range, driven by the Bow force. I've found that it covers the quietest of string accompaniments, through to the loudest bowing, without needing fader automation. This way, you get the full character of the instrument as it is played in different ways.

Up bow, down bow

[You can skip this one for most purposes] We provide a Bow direction macro to introduce some textural changes to the sound. To be honest, we haven't prioritized modelling this precisely, because a player will exploit or naturally compensate for the differences while playing, and they can mostly be covered by the other controls of the instrument. It's your choice whether you use these. Most of the imagery of bowing can be created by controlling the degree of continuity in your sound, and how the bow re-engages to resonate the string. On the other hand, you might want to explicitly use the Bow direction macro, and modulate it to reflect the convention of landing the stronger on-beat notes with the down direction, without explicitly expressing those in more fundamental terms. You might also want to tweak how this macro affects the sound of the instrument, because we haven't prioritized getting this right.

Bite, grit

We'll find a better word for this, or automate it into other controls. If you increase the Grit, the bow will imperfectly engage with the string, and rather than exciting it at regular micro-intervals, the bow excites the string infrequently and with more force every time it loses grip.

With this, you can simulate a bow landing on the string while the bow is moving, and introduce more energy into the body of the instrument. Short bursts are most effective, as the bow settles into a smooth glide. Use in combination with Bow force and Bow speed for a more authentic sound.

Slur, glissando

It's best to do these with a pitch bend to match the profile of your movement on the finger board, and combine that with any changes in bowing force or speed as your note transitions. The instrument compensates the energy of the string to match.

You can combine pitch bend for major movement, with Finger vibrato for finer movements.


If you want a casual vibrato, you can just increase the value of the Vibrato macro. That should work well for instruments that sit quietly in the background, string sections, or for short and occasional foreground notes. However, your listeners might soon detect that the vibrato is uniform, and become distracted by the performance. If you need the authenticity and extra control of your vibrato technique, then use Fingered vibrato.

Fingered vibrato

Use the Fingered vibrato macro controller, to introduce explicit small pitch expressions to your playing. On a controller graph, that looks like a squared-off sine wave around the midpoint. The extent of a full-amplitude pitch variation of this macro is 34 cents either side of your note. This is usually enough range, but if you think you'll need more, then increase the mapping from this macro to the pitch value of OSC1.

Hint: If you apply fingered vibrato afterwards to an existing track, then it's best to do so after all tempo changes are applied. If you later apply tempo changes, the vibrato rate will scale with your tempo change.

As a bonus, you could introduce imperfections in your playing, say to overshoot or undershoot slightly, or to approximate the intended pitch. You might simulate 'correcting by ear' after the interval that an intermediate payer might. You could also play slightly sharp or flat, to add mood or relate to harmonic ratios.

Usually though, you can approximate the imperfect settling on a note with fingered vibrato, knowing that if you have your pitch bend perfect, then the fingered vibrato value straightforwardly represents the deviation from the perfect note.

Ring damping

You can mute strings more deliberately by ending the note, mapping a controller to nudge downwards the Mix parameters of both AW effects, and reducing Amp Eg Release.



This isn't yet implemented on this instrument, and you'll need a different patch for that. However, if you want to repurpose a patch and excite OSC1 with a pluck profile, that works really well, and you get the full response of the instrument body.

We plan to make pizzicato available as a separate instrument, which will be compatible with your DAW workflow if you're accustomed to using separate samples or tracks for each articulation.


Start the note with higher Bow force on notes you wish to accent. If you're starting the note from a resting bow, then a faster onset and higher peak of Bow force will achieve accent, compared with other notes.

For more demanding, heavy, and short notes, a short application of the Grit macro might help add scratchiness.

Au talon, heel, frog, nut

Not yet mapped. See [Future developments].

Bariolage, finger position

The instrument does not have explicit string assignment, nor 'position'. However, you can use the macro controller Open string to change the character of the note, from fully open, to fingered, and higher position. It is not accurately mapped, and is probably not useful in its current form, but I plan to improve it.

Double stop

Provided both the played strings have the same modulations (slurs, glissando, vibrato, etc), you can play two notes in the same track or channel. If you modulate the strings independently, you'll need to use two tracks, or use MIDI MPE mode, or an alternative protocol, to control your notes independently.

Flautando, sul tasto

(Bow towards the fingerboard) Not yet mapped, but you can work towards the effect by trying:

- Adjust tension higher. - Use Filter 2 to add a weak bandpass filter or highpass filter.

See also: Flute whisper.

Sul ponticello

(Play with the bow near the bridge)

Not yet mapped. See [Future developments].


Use a faster onset and higher peak of Bow force, on a short note.

For more demanding heavy notes, a short application of the Grit macro might help add scratchiness.


Draw each bowing action in the Bow force controller. If you have set up Bow direction, then alternate it with the same timing as the sawtooth. This will require a high density of control data, so you might choose to map a controller to an LFO and control the amplitude of the LFO instead.

You can play fingered tremolo with the Pitch bend. If you want a more detailed rendering, and if you have any remaining margin, you can place short upward bumps in the Bridge mute to fake the disruption to the string's harmonics as the fingering changes.

Future developments

I hope to:

  1. Make the response to bow force tighter.
  2. Introduce the 'flute whisper' for playing lightly and on the cusp of resonance.
  3. Implement the sound of positions
  4. Implement the sound of flautando, sul ponticello, sul tasto.
  5. Review the controllers used, find a way to consistently extend capabilities, and find a consistent controller convention that better helps moving parts between instruments.