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:
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.