I think percussion is a good idea. It allows your child to have good sense in rhythm and it is fun! Mummy may try XX percussion centre. My daughter started when she was around 3 years old and she still likes it very much.
當然如果妳發現小朋友對音樂在興趣,又或者有天份的話,可以考慮在四、五歲時讓他們開始學習樂器。若有天份的話,最好就跟 professional 的老師,因為分別會很大。由於我對音樂的認識有限,我的兒子就是發現得遲,去年才轉了跟 professional 的老師學鋼琴,在技巧上有很多地方要去改善,起步比起一些自少跟 professional 老師的小朋友慢了很多。