musica de intervencao

Just to confirm before I write: do you want a factual piece about the real historical genre often called "música de intervenção" (intervention music), which describes music that supported state actions or regimes in Portuguese-speaking contexts (notably Brazil and Portugal), or would you prefer a purely fictional, creative description inspired by that name?

If you want the factual version, I can provide a 500-word description with:
- the birth era (roughly mid-20th century under authoritarian contexts),
- how and why it emerged as a distinct category,
- key artists and ambassadors (notable figures who endorsed or were associated with state-driven music),
- geographical focus (Brazil, Portugal, and any other regions where it had a presence),
- characteristic themes, musical traits, and production contexts,
- important historical and cultural nuances, and
- its reception and legacy today.

Please also tell me whether you want it in English or Portuguese.