So you know how music can sound different depending on where you are in the world? Like how the music you hear at a rodeo might sound different from the music you hear at a party in Japan. Well, in Indonesia, there's a type of music called gamelan that's really popular. It's made up of lots of different instruments, like gongs, xylophones, and drums, and they all play together to make really beautiful sounds.
Now, sometimes people from other countries hear gamelan and they really like it. They think it sounds cool and want to try playing it themselves. So they might bring some gamelan instruments back to their own country and start playing gamelan music there. This is called playing gamelan outside of Indonesia.
Even though it's not from their own country, people who play gamelan outside of Indonesia still really respect the original traditions and ways of playing the music. They might even bring in teachers from Indonesia to help them learn how to play correctly. And sometimes they might even put their own twist on the music, making it their own while still honoring where it came from.