The framing is OK, but the far end of the instrument is out-of-focus and also partially blocked by the plant. Did you use a tripod and a fairly small aperture (e.g., about f11) for this shot? If not, that's what you should try. Manually focusing partway into the scene is also advisable to get foreground-background sharpness; I'd probably focus on the strings near the hole in the body. If this doesn't make the whole thing sharp with the lens you're using, then you may have to tip the instrument up so the difference in distance from the camera to the ends of the instrument is smaller.