Surge synth is a free and open source synth plug-in for AU and VST audio workstations. If it weren't free, it would still be among the best. It's versatile tool that can create a wide range of sounds.
The patches in Surge XT that I designed:
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 of the violin:
|1||41||Bow speed||Affects 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.|
|2||42||Bow force||Set above zero to make a sound. 60% is good for a resonant note without introducing inharmonic sounds.|
|3||43||Bridge mute||Dampens the sound. The lowest setting is unnaturally rich in high frequencies, but you might want to use this effect creatively.|
|4||44||Bow direction||Experimental: changes the tone of the sound.|
|5||45||Finger vibrato||Manually modulate the pitch of the note, which also slightly affects the loudness of the sound|
|6||46||Open string||Experimental: allows the note to resonate without finger damping.|
|7||47||Grit||Adds 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.|
|8||48||Reverb||Controls 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.
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.< >
The Cello is based on the violin, with some parameter tweaks to customize the sound. See Violin 2021, as the controllers are mostly the same.
The instrument can be played with some of the variations allowed by the physical original.
You can use multi-track techniques to isolate expression control of more than one string, or enable MPE in Surge and your DAW.
|1||41||Mute||Lowers the high-frequency components of the guitar.|
|2||42||Soft pluck||Set low, this gives a hard pluck with sudden excitation of the string. Set high, this rubs the string with a finger pad as it is released, for a soft excitation.|
|3||43||Play at bridge||When high, the sound is harsher with more high harmonics and body resonance for the pluck.|
|4||44||Banjo||Introduces specific body resonances for the banjo drum, and decreases the ringout.|
|5||45||Dual string||Adds a second string to the mix, which you can detune in the oscillator parameters.|
|8||48||Reverb||Adds a room ambience.|
This is the start of Cavatina (Theme from the Deer Hunter) by Stanley Myers. It uses vibrato on the modulation wheel, with expressions of Soft pluck and velocity. The pitch wheel controls any transitions between frets.