I tried, using a USB A to USB B cable but the computer did not recognize the Clavinova CLP-230 in Garageband. Not sure where I am going wrong? Tried a different cable but still no luck. OS 10.13
You'll need to install the Yamaha USB-MIDI driver first:
This driver works across all the Yamaha Clavina models with USB port for MIDI.
When you have installed the driver, reboot the Mac and insert the USB-cable from Mac to piano. Then turn on the Piano. Finally start GarageBand, and the new MIDI device should be available for use.