RIO DE JANEIRO (AP) — Homegrown trap is the fresh sound of the favelas, and remains largely unknown outside of them. Featuring a lyrical flow over synthesized drums, it is an offshoot of Atlanta-style trap and speaks to the day-to-day struggles of hardscrabble hoods. Except most of these rappers aren’t gangsters, though their millions of YouTube viewers wouldn’t know it from their videos that show them flaunting what appear to be real guns in working-class neighborhoods dominated by drug traffickers. However popular the music had become, some authorities are highly critical, and police are investigating one duo and their video.