Look up piano stool in Wiktionary, the free dictionary.
A piano stool, also referred to as a piano bench or piano chair (depending on style) is a seat especially designed for use at the piano, which can provide more playing comfort than a normal chair.[citation needed]
Its height is usually adjustable to accommodate players of various sizes. It is often padded, either with an integrated foam-filled cover or a purpose-made detachable cushion. In its bench form, it sometimes has a hidden compartment for storing music sheets and other supplies.