The Kalimba Harmony™ is pre-tuned in Key C.
Yet, sometimes like when playing any instrument, tuning is required.
There are two great approaches to tuning your Kalimba Harmony:
Option 1: Get yourself a real tuner. (This may be more ideal, if you are more traditional, and less experienced with technology)
Option 2: Download a tuner app on your smartphone.
Here are two great apps which you can use:
Android system app: gStrings
Apple system app: Instuner.