Rhythm instruments are musical instruments that are used to add rhythm and beat to a song or performance. They include drums, tambourines, shakers, and other instruments that help keep time and create a groove in the music. Full definition
This Amazon page provides tons of inexpensive suggestions for rhythm instruments for children. (childdevelopmentinfo.com)
As your child gets older and a little more coordinated, try rhythm instruments that can be banged, like drums, cymbals, or xylophones. (kidshealth.org)