A stringed instrument having a stationary support; one part of the instrument interfacing with the musician's sternum, another part pivotally interfacing with the support using two pivot axes mounted perpendicular to each other, first axis dependent on second axis. The longitudinal axis of the instrument is aligned with the musician's anatomical median plane; the support enabling congruent movement between the instrument and the musician's swaying torso while preventing rotation of the instrument around its longitudinal axis, thus improving ergonomic posture and technique. The instrument has an effective string length less than that of a cello and greater than that of a viola, for enabling such ergonomic positioning.The instrument further has a non-traditional nut-bridge configuration for a more ergonomic fingerboard topology and alignment of known points of contact; further, the instrument has a modular fingerboard for simplified assembly and convenient interchange of either the fingerboard or the instrument; further, the instrument has a geared tuning system, enabling tuning by sliding a finger tangentially along a wheel, for more intuitive tuning by translating linear pitch perception into linear finger motion.