Stringed instrument comprising: - a unitary structure formed integrally by a body, a neck and a head; - front panels (13A, 13B, 13C) that seal the body at the front and are connected to said body through connection means; - rear panels (21A, 21B) that seal the body at the back and are connected to said body through connection means, wherein said head has holes for mounting tuners with corresponding pegs, characterized in that said unitary structure is formed from a solid block of rigid non-wood material by computer numerical control machining; said body comprises: a front part with a plurality of cavities and / or housings arranged at predetermined locations and intervals and at least some of said cavities and / or housings communicated internally by openings arranged in the side walls thereof to form an interconnected network; and a rear part with housings (45, 46) for the housing of the structure of a tail piece that is integrally comprised in said unitary structure and of a power source respectively, and open chambers that extend between said front part and said rear part and are delimited by at least some internal ribs; said neck comprises a side wall provided with fixing means for fixing a fingerboard (2, 2'), a bottom wall and a central rib; said stringed instrument additionally comprises a metal fingerboard (2,2') with a compound radius, machined by CNC from a solid block of rigid non-wood material as a single piece and connected to said unitary structure in a removable and interchangeable manner, through connection means arranged on the lateral walls of the fingerboard (2, 2') that allow the fingerboard to be connected laterally and are complementary with the fixing means arranged on the neck; and said stringed instrument additionally comprises a bridge machined by CNC from a solid block of non-wood rigid material and mounted on the front part of the body. - a unitary structure formed integrally by a body, a neck and a head; - front panels (13A, 13B, 13C) that seal the body at the front and are connected to said body through connection means; - rear panels (21A, 21B) that seal the body at the back and are connected to said body through connection means, wherein said head has holes for mounting tuners with corresponding pegs, characterized in that said unitary structure is formed from a solid block of rigid non-wood material by computer numerical control machining; said body comprises: a front part with a plurality of cavities and / or housings arranged at predetermined locations and intervals and at least some of said cavities and / or housings communicated internally by openings arranged in the side walls thereof to form an interconnected network; and a rear part with housings (45, 46) for the housing of the structure of a tail piece that is integrally comprised in said unitary structure and of a power source respectively, and open chambers that extend between said front part and said rear part and are delimited by at least some internal ribs; said neck comprises a side wall provided with fixing means for fixing a fingerboard (2, 2'), a bottom wall and a central rib; said stringed instrument additionally comprises a metal fingerboard (2,2') with a compound radius, machined by CNC from a solid block of rigid non-wood material as a single piece and connected to said unitary structure in a removable and interchangeable manner, through connection means arranged on the lateral walls of the fingerboard (2, 2') that allow the fingerboard to be connected laterally and are complementary with the fixing means arranged on the neck; and said stringed instrument additionally comprises a bridge machined by CNC from a solid block of non-wood rigid material and mounted on the front part of the body.