Antibacterial compositions having high antibacterial effectiveness and excellent esthetic properties are disclosed. The sensor array is charged by a sensing signal corresponding to an external light in response to a driving signal during a first time period and discharged in response to a switching signal during a second time period. Any atmospheric pressure to a sub-critical andor supercritical state can be employed as the production conditions. A fluid, such as a liquid, is disposed within the connector and the tubing at a pressure higher than the environmental pressure. With this embodiment, when a performer’s fingernail hits the top surface of the white keys while using the keyboard apparatus, the production of an unpleasant sound can be avoided. The siding panel has at least one protrusion disposed along at least one of the faces, wherein the at least one protrusion provides an air gap between the siding panel and a face of a second siding panel when the siding panels are installed in a siding panel assembly.