Within an Orff-based program implemented in Israel, this mixed-methods study examined the effects of age on emerging rhythmic literacy in children. Participants (N = 132) were kindergarteners (n = 45) and first-graders (n = 87) aged 4 to 7.8 years. The participants performed a rhythm entitled "Rhythm-A" through the body and instrumental percussion and then were required to create a self-invented notation of the rhythm. A one-session literacy intervention program, based on teaching standard rhythm notation, followed with randomly selected first-graders (n = 44). Its purpose was to investigate the effect of standard notation instruction on children's ability to notate Rhythm-A. Results indicated (1) a significant age effect on children's emergent rhythmic literacy and (2) a significant effect of a one-session literacy intervention program on participants' post-intervention notations. The study has relevance to research on Orff-based music education and music literacy.