Japanese occupation era In 1943, Oetomo worked as an employee at the Police Court (軽罪法院, keizaihōin, Kunrei-shiki: Keizai Hooin) in
Jatinegara. The following year, he took the entrance exam for the Judicial Training School (司法監理養成所, shihōkanriyōseishō, Kunrei-shiki: sihookanri yooseizyo) located in
Salemba (now the Postgraduate and Doctoral Campus of the ) and passed on 23 March 1944. In 1945, Oetomo became a prosecutor at the Surakarta District Court.
Post-independence In 1947, Oetomo became the personal secretary to the Military Governor of Surakarta at that time,
Wikana. He then joined the Indonesian Communist Party (PKI) and became a candidate for the
Constitutional Assembly in the 1955 general election from the Central Java electoral district. Oetomo was successfully elected as a member of the Constituent Assembly and served from 9 November 1956 until its dissolution on 5 July 1959. Apart from becoming teacher and politician, Oetomo was also an active painter in the Surakarta branch of Lekra (
Lembaga Kebudayaan Rakyat).
Mayor of Surakarta In the
1957 local legislative elections, the Indonesian Communist Party (PKI) won 17 out of 30 seats in the Surakarta City Council. On 20 February 1964, five music organizations took the initiative to form the Association of Indonesian Music Organizations (HOMI/Himpunan Organisasi Musik Indonesia) with the aim of improving the quality of music and ensuring that music in Indonesia aligned with the state's direction at the time. Oetomo, as both the mayor and an artist, acted as its patron. == Post-30 September Movement ==