This is a standard in the Shona repertoire. After you learn to play it as written above learn it the following way.

These are the same notes in the same order but the beat is in a different place. Remember, although it may be easier to memorize this piece thinking of each measure as 3 groups of 4 notes, the beat is 4 groups of 3 notes. Tap your foot to the beat. After you learn it with the beat in both places, find a friend and play both versions simultaneously.

An easy variation is to play every other left thumb note an octave lower, like this.

---