A collapsible acoustic guitar has a body divided into upper and lower halves, a detachable neck and a detachable string assembly consisting of headstock with tuning pegs, strings and an anchor member. In the preferred version, the upper body half nests in the lower body half and holds the neck and string assembly. In another version, the upper half is hinged to the lower half. The anchor member is used with a tensioning clamp and pivoting handle to loosen the strings for removal of the headstock and to tension the strings when the guitar is re-assembled.