Scenario; My bard character, a harpy, is proficient with an instrument(voice), and has expertise in performance. How does that roll play out? Does expertise in performance make the instrument proficiency irrelevant?
Also does scenario make a difference here? Examples; simply performing to perform, causing a distraction or charming a person/crowd?
I put forth the logic to my GM that one's voice can be considered an instrument when used to sing and that my harpy was a gifted singer for double proficiency(the same way as for expertise for other skills). As well we agreed any changes in the natural abilities and skills have to have an equal or greater counterbalance in the character. As such my harpy bard does not like to sing due to her racial ability to lace her singing voice with magic that can charm others. The block is entirely mental and ultimately false as she could simply not use the luring song if she tried, but she doesn't believe she has that control and thus refuses to sing, period. Instead she plays the violin. My GM liked the restriction I placed on myself and I am looking forward to role-playing this character through her trauma.