Neosantara is my contemporary indonesian music spotify playlist
YESNOWAVE is a frank and fearless label promoting indonesian music via free releases, including lots of political, unorthodix and left-field releases.
madrotter treasure hunt is an amazing trove of indonesian cassettes and vinyl otherwise lost tothe internet.
Sumarsam is an east Javanese lecturer in Indonesian music theory and his pedagogy for Western students is good, and freely available.
Gamelan Bali (Even further east)
Austronesian Outpost of Anaphoria is an imaginary island that happens to use many tricks from the Nusantaran gong tunings.
Sethares on tuning systems generally, and the weird things that happen in south east asia especially.
Jalanan, the busker movie.
I know more about sundanese music specifically, so that has its own page.