Rhythm is a difficult concept to teach to children and adults. I find that the actual “separation of rhythm from notes” is the first concept that must be understood. I have students either tap, clap or snap the rhythm of the right hand and left hand separately. The linear understanding of the beat underscores the actual playing of notes. I use rattles, shakers, African drums, and more recently colored sticks to tap the LH and RH rhythm as the notes are visually being tracked by the student. More recently I found Electric Drumsticks on Amazon; these light up when tapped and create another way of attracting the visual learner to make a connection to the beat.