Placoso is a slang term, particularly used in Mexico, to describe someone who is a gangster, a tough guy, or a member of a street gang. It implies a certain street credibility and often a connection to illicit activities.
In the song, Aleman raps, "Ando con puro placoso," meaning "I hang out with only tough guys/gangsters." This word is interesting because it's not a standard dictionary term, but rather a vibrant piece of street slang that gives insight into the song's gritty context and the artist's persona.
"Requisito 420" is a laid-back collaboration between Mexican rapper Alemán and Argentine artist L-Gante. The title plays on 4/20, the number associated with marijuana culture, and the song sets out its own "requirements" for a good night: good weed, good drinks, and good company.
Alemán raps about staying sharp and confident even with a cop watching and rivals talking behind his back, while enjoying the small luxuries that come with success, like a nice car and expensive clothes. L-Gante brings his own Argentine slang and swagger to the second half, describing a night out with friends, a Mercedes, and no patience for anyone who looks at them the wrong way.
More than anything, the song is a celebration of the two artists teaming up across borders. The closing lines, "Compa, Alemán / México y Argentina," spell out exactly what the track is about: Mexican and Argentine talent meeting on the same beat.