In the main palace in my world, there are no soldiers or guards, and in their place, there are musicians. This is because the musicians have instruments that double as weapons, and they have been trained to provide entertainment for the royals as well as to finish off any intruder that sneaks inside the palace.
My question is, what would be the most seamlessly hidden way of implementing a weapon into the musicians’ instruments, and kills the intruder the quickest and most efficiently?
Their instruments are mostly lyres and harps with a violin player as well.
The technology they have access to is advanced enough for blades and arrows and small firearms such as pistols (no automatic targeting or sensors or things like that) but they do not have many synthetic resources, instead they use materials such as metal or stone.
(Edit: I tagged my question as science-based because I preferred to have real-world answers, but if you have an interesting idea that’s not really realistic please do share anyways!)