Does taking the back plate off a guitar do anything to sound?

Yes. Removing the back plate of a guitar can affect the sound of the instrument. The back plate resonates with the sound waves produced by the strings, and this resonance can affect the overall tone and sustain of the guitar. Removing the back plate can result in a brighter, louder, and more resonant sound. However, it can also make the guitar more susceptible to feedback and other unwanted noises. Ultimately, whether or not to remove the back plate is a personal preference and depends on the desired sound of the guitar.