A guitar constructed for so-called "one-touch" tuning including a pivoted lever that is movable between string relaxing and string tensioning positions, and is held in the latter position by a releasable latch. The lever is secured to a string by a ball-like retaining member that is clamped to the string at a predetermined location near the tail end thereof. Preferably, this clamping takes place shortly prior to securing the string to the lever. The retaining member is provided with at least one groove through which the string extends. The retaining member is deformed by crushing same at portions thereof that defines at least one groove thereby collapsing the groove around the string to firmly clamp the retaining member to the string.