Abstract: In a porch or patio railing system having a plurality of vertically disposed pickets, a harmonic stabilizer for dampening forced external harmonic resonance is applied thereto. Each harmonic stabilizer includes an elongated member having a c-shape configuration formed by three wall members including a back wall and a left and right side wall all integrally attached at right angles in relation to one another. A center channel of the elongated member is defined by the three side walls and also includes an open end for providing access to the center channel. A pair of inwardly extending notches attached along outer edges of the left and right side walls provides a friction fit mating mechanism when the harmonic stabilizer is employed onto one of the plurality of vertically disposed pickets.