A locking fastener for a guitar strap which receives the end pin of a
guitar includes a base plate and a locking plate which is reciprocatingly
slidable on the base plate. The base plate has a pin receiving keyhole
formed through its thickness which is defined by a widened opening and a
narrowed opening. The base plate also has a central slot formed through
its thickness and openings or detents which are spaced apart from one
another. The locking plate has a front edge which is recessed to define
an open pocket, at least one protrusion which is selectively received in
the openings or detents to secure the locking plate in a desired position
with respect to the base plate, and a knob post or handle which extends
through the central slot of the base plate and which is graspable by a
user. By sliding the locking plate with respect to the base plate, the
user may effectively change the size of the pin receiving keyhole to
secure or release the end pin of the guitar from the locking fastener and
strap attached thereto.