Piano seat with automatic height adjustment consisting of a structure formed by: - A first pair of scissor-type mechanisms or articulated structure in the form of an "X " arranged in a facing manner, there being, at its ends, a lower stationary point of articulation (1.1), and a lower movable point of articulation (1.3) at the bottom, whereas the upper ends have an upper stationary point of articulation (1.2) and an upper movable point of articulation (1.4). - a second pair of scissor-type mechanisms or articulated structure in the form of an "X", arranged in a facing manner, there being, at its ends, a first lower stationary point of articulation (2.1), and a first lower movable point of articulation (2.3) at the bottom, whereas the upper ends have a second upper stationary point of articulation (2.2) and a second upper movable point of articulation (2.4), characterized in that the lower articulations occur in - two lower "L"-section angular profiles arranged in a facing manner, while the upper articulations occur in - two upper "L"-section angular profiles arranged in a facing manner, the facing articulations, both at the bottom and at the top, stationary and mobile being joined together by connecting bars, wherein above each of the profiles there are individual oblong slots (3.1), (3.2) made in the lower "L"-profiles,, whereas with - oblong slots (4.1) and (4.2) made in the upper "L" profiles, wherein the upper "L" profiles are further connected together by - intermediate transverse bars,, and and wherein the assembly is moved by raising or lowering by - a first gas spring and a second gas spring, which are actuated by - two actuators and - A first pair of scissor-type mechanisms or articulated structure in the form of an "X " arranged in a facing manner, there being, at its ends, a lower stationary point of articulation (1.1), and a lower movable point of articulation (1.3) at the bottom, whereas the upper ends have an upper stationary point of articulation (1.2) and an upper movable point of articulation (1.4). - a second pair of scissor-type mechanisms or articulated structure in the form of an "X", arranged in a facing manner, there being, at its ends, a first lower stationary point of articulation (2.1), and a first lower movable point of articulation (2.3) at the bottom, whereas the upper ends have a second upper stationary point of articulation (2.2) and a second upper movable point of articulation (2.4), characterized in that the lower articulations occur in - two lower "L"-section angular profiles arranged in a facing manner, while the upper articulations occur in - two upper "L"-section angular profiles arranged in a facing manner, the facing articulations, both at the bottom and at the top, stationary and mobile being joined together by connecting bars, wherein above each of the profiles there are individual oblong slots (3.1), (3.2) made in the lower "L"-profiles,, whereas with - oblong slots (4.1) and (4.2) made in the upper "L" profiles, wherein the upper "L" profiles are further connected together by - intermediate transverse bars,, and and wherein the assembly is moved by raising or lowering by - a first gas spring and a second gas spring, which are actuated by - two actuators and