One way to play samba on a keyboard is to use the "rhumba" or "cha-cha" rhythm pattern. This pattern involves playing a series of eighth notes in a syncopated rhythm, with the accent falling on the second and fourth beats of each measure. You can create this rhythm by using the left hand to play the bass notes and the right hand to play the melody and chords.
Another technique that can be used to play samba on a keyboard is to use the "clave" rhythm. The clave is a five-beat pattern that is essential to samba music. It can be played by using the left hand to play the first and third beats of the measure and the right hand to play the second, fourth, and fifth beats.
In addition to these techniques, there are a number of other things you can do to create an authentic samba sound on a keyboard. For example, you can add a layer of percussion by using the drum pads or the sequencer to create a simple samba beat. You can also add a touch of Brazilian flavor by using sounds like the cavaquinho, the pandeiro, or the berimbau.
With a little practice, you can learn to play samba on a keyboard and create your own authentic Brazilian music.