There is provided a keyboard apparatus which has a high durability, portability,
and operability, and facilitates adaptation to a wide range of musical scenes and
to multi-model production. Each adjacent pair of four main cases are pivotally
connected to each other via connecting portions, whereby the main cases are allowed
to assume a folded position which enables the keyboard apparatus to be carried
with ease, and a flat unfolded position in which the keyboard can be played. Each
main case has a keyboard unit arranged therein. Three main cases for lower tone
ranges each have four white keys arranged therein, and a main case for a highest
tone range has three white keys arranged therein, and a total of 25 keys
are arranged on the keyboard apparatus. The main case for the highest tone range
also has a group of operating elements arranged therein.
