Just connect an piezo to the board and you are good to go. Pin 11 is used in every sketch because some piezo speakers can be connected between it and the close GND pin without any wiring. You can use ...

A digital metronome using Arduino UNO. Additional materials include: an LCD display, two piezo buzzers, eight LEDs, and six push buttons. - geeyana/Arduino-UNO-Metronome ...

My daughter likes buttons. She's learning letters. I was bored over winter break and had these parts laying around... so I built her a "Button Box" based around an Arduino. Open source, hackable ...