I've been toying with the idea of a feat for a bard to allow for more sneaky play with things like mass suggestion. I think it could be fun and I was thinking of suggesting it to my DM for the bard I am currently playing down the road in the campaign.
Whenever you are making a performance, you can weave magic into your performance without being detected as the caster. The somatic and verbal components of a spell are woven seamlessly into your performance, masking the origin of the spell cast.
If a member of your audience would be expected to recognize magic being cast (DM discretion for what this means practically), you must pass a performance check against their perception to successfully hide the spell.
It's a bit like the subtle spell effect for sorcerers, but limited to contexts in which you are performing for an audience.
Is this feat balanced, or even useful?