I'm not clear on exactly what your issue is - Microphone and Camera permission shouldn't have anything to do with the app playing back sounds.
However, there really isn't any reason not to give SeeMusic permission to use your Microphone and Camera - the app doesn't transmit any data online, so there is 0 possibility of any of your microphone or camera data being used in any way you don't intend. I'd recommend just giving the app Microphone and Camera permission if that seems to be causing an issue.
I'm not clear on exactly what your issue is - Microphone and Camera permission shouldn't have anything to do with the app playing back sounds.
However, there really isn't any reason not to give SeeMusic permission to use your Microphone and Camera - the app doesn't transmit any data online, so there is 0 possibility of any of your microphone or camera data being used in any way you don't intend. I'd recommend just giving the app Microphone and Camera permission if that seems to be causing an issue.