An electronic keyboard instrument includes a casing of a rectangular shape having a bottom plate disposed to face a loading surface, and a keyboard provided in connection with the casing and having multiple keys aligned in a longitudinal direction of the casing, and the bottom plate includes multiple fixing legs protruding from the bottom plate towards the loading surface and configured to come into contact with the loading surface to thereby support the casing from below and a first adjustment leg disposed outside the fixing legs in an aligning direction of the multiple keys, and the first adjustment leg protrudes from the bottom plate towards the loading surface and is spaced apart from the loading surface.

A sound source includes (i) one or more memories storing instructions and one or more processors configured to execute the instructions, (ii) one or more circuits, or both (i) and (ii) configured to: obtain a setting instruction; generate first information defining a key-damper half zone or a key-damper half point for sound production for each of a plurality of keys of an electronic keyboard instrument in accordance with the setting instruction; and output the generated first information.