The sounds and ideas on YRN — sproingy cheap synth melodies, cave-in-your-eardrum bass, candy-colored cartoon-thug sentiment — have been staples of Atlanta’s rap underground for many years, but we’ve rarely heard them with the sort of spirited glee that the young guys in Migos bring here. They bounce their voices off these cheap and ingratiating melodies with such goony energy and rhythmic inventiveness that you almost don’t notice that most of the songs are about selling drugs. And if old heads have trouble divining the appeal of, say, the drilling-into-your-brain “Versace” chorus, they should consider that the words-as-superballs beats-as-playground spirit is the same thing behind, say, Das-EFX’s Dead Serious. –Tom [LISTEN]