In all stringed acoustic instruments, the soundpost is a cylindrical length of wood extending from the top to the bottom (front to the back) of the instrument. It is designed to provide rigidity to the instrument to improve the resonant quality of the wood. It is, indeed, NOT glued to the instrument, it is held in place by friction, and without the tension of the strings, is quite easy to move. It, along with the bass bar, are the main methods of altering the tonality of an instrument. When looking at the front of an instrument, the soundpost is located just below the right foot of the bridge.