I have 88 keys
but I can’t open a single door.
What am I?

A piano.. 52 white keys + 36 black, all the way from A0 to C8. The most useful collection of keys that opens nothing.

Question

Accepted Answer

A piano. — 52 white keys + 36 black, all the way from A0 to C8. The most useful collection of keys that opens nothing.