Not many people know the first person that sang Indonesia Raya. Do not expect about knowing it, many people may not even ask about it. She was Dolly Saling – her real name was Theodora Athia Salim – the daughter of the national hero that spoke many languages, Agus Salim.

At that time, Dolly was representing a scouting organization, National Indonesische Padvinderij (Natipij), under the auspice of Jong Islamieten Bond (JIB) which advisor was Haji Agus Salim.

After generating important resolutions to continue Indonesia independence fight, Kongres Pemuda II was closed by Indonesia Raya song performance. W.R. Supratman, the song's composer, accompanied the song with his iconic violin.

“Audiences were immediately excited with the song and requested repetition. Dolly, one of the young girls attended, the first daughter of Haji Agus Salim, sang the lyric”, wrote Rosihan Anwar in Sejarah Kecil Petite Historie Indonesia Jilid 2.

Dolly sang the lyric without seeing the text. After the performance, applause was thundering in the historical building. Since then, Dolly Salim was pronounced as the first person that sang Indonesia Raya.

(source)