Angklung is very a popular musical instrument from South East Asia. I've experienced playing Angklung with kids a few weeks ago. It was such a fun.
Basically Angklung per set contains 40 instruments with different notes. So, each pupil will only focus to play his own Angklung. Then, all combined together becoming a nice melody.
Who taught angklung? The school invited a private teacher and explain the lesson well to the music teachers. In addition, he gave a few musical books as teachers' reference.
I'm not a music teacher. I just want to be involved in the activity. The experiences is priceless.