Abstract: A dual-inline neck truss system in a stringed musical instrument is disposed uniformly along the instrument neck, generally toward the rear side, opposite the front side that forms or supports a fingerboard or fret-board. The truss system may be a two-portion single member or two separate in-line members, and is enclosed close to the rear surface of the neck or else with a surface exposed along its full length and made flush with the rear neck surface, smooth to the touch. The truss system is secured to the neck at a designated intermediate location so as to form two substantially co-linear truss portions, either of which can be adjusted for tension independently via manual adjustment hardware for applying pressure against opposite end regions of the neck, thus enabling special desired instrument setup for optimal string-to-fretboard/fingerboard spacing, e.g.