The best reflector for sound will be massive, rigid, and with a smooth surface.
Reflector.
The amount of light a material reflects depends upon the kind of material in the reflector, the extent to which it is polished , and the angle at which the light strikes the surface. your welcome.
hard stuffs
The kind of guitar they use in safe and sound by Taylor swift is a Taylor guitar. That kind of guitar is one of the best guitars you can get.
rough texture and dark color
silk cloth =P
Sound is a kind of energy.Sound is a kind of energy.Sound is a kind of energy.Sound is a kind of energy.
Denser material, higher speed.
In my opinion, an acoustic plug-in guitar sounds best. You can plug it in and amplify the sound, and if you plug in a sound head, switch to distortion. It's funny.
This is a matter of opinion. And it depends on what you need the stereo sound system for. Do you want it for bass? For surround sound? These factors will affect your selection.
A single-mirror reflector.
This needs more information. We don't know what kind of 'removable surface', and if you still want it to be removable.