One of my players messaged me about a new character they were creating, and they proposed the concept of a mute bard. Long story short, they wanted to RP a cursed character, and I was really intrigued by the idea.
However, I know about the mechanical impacts of a bard that can't speak, verbal spellcasting, as addressed in Can you cast verbal components if you have no tongue?
For reference, these are the traditional requirements for Verbal components:
(PHB, p. 203): Most spells require the chanting of mystic words. The words themselves aren’t the source of the spell’s power; rather, the particular combination of sounds, with specific pitch and resonance, sets the threads of magic in motion. Thus, a character who is gagged or in an area of silence, such as one created by the silence spell, can’t cast a spell with a verbal component.
Emphasis mine
The idea we came up with was that the character had figured out how to fulfill the verbal component of spells using their bardic instrument (their viola). Checking the restrictions mentioned above, this still produces sound, so it will still be affected by a silence spell.
The main impact I can notice from this is that they will no longer be able to complete purely verbal spells while bound or separated from their instrument. In a way, it's kind of like having an arcane focus?
The only benefit that could arrise from this that I could think of is that the player could freely cast in a place where breathing was difficult (underwater, poison cloud, etc)
So, my questions are...
What other unique scenarios could this character encounter with this change?
Will this give the PC an unfair advantage/disadvantage?
Is there a better way to have a mute Bard with minimal mechanical impact?
The player has also mentioned a desire to build their weapon into their instrument so they don't have to un/re-equip their weapon and instrument during combat, but I'll leave that for another question.