Speed?
Violinist here.
Violins make sound by dragging the bow (stretched horse hair) over a string, causing the string to vibrate. At the micro level, the bow pulls the string to one side using friction, until the tension on the string pulls it back - this happens hundreds of times per second, and forms the basis of the sound we hear. Horse hair is slippery by default. To create the necessary tension violinists apply a small amount of solidified tree resin by wiping a piece along the length of the bow. This piece of hardened resin has the same approximate texture as glass or hard candy, and is called rosin.
Why not use a fiber that’s not not stretchy, and also not smooth? How would using a synthetic fiber affect the sound?
Originally? Probably lack of options. These days the aim of the game is sounding “like a violin”, so naturally there’s very little innovation in violin technology.
Rosin
Which is also a type of cannabis concentrate, lol
Rosin, I think
Alternative hint: “Johnny _____ up your bow and play your fiddle hard.” From The Devil Went Down To Georgia
Solo Time: nannnannaeeeerrr naw nanaeeer nNannnnnnaaaawweeeerrrnnnannnwwweerrrr ddddddrrreeeeeeeeeenanannananannanaaeeeeeeeeeweeeeeeeewweeweerrrerrrrrteeeeeeeee^f