Richmond’s Noah-O has something serious to say with “Oh My,” the lead single from his new mix tape, “Thug Wilder 4 President.” As he raps early in the song, his goal is to “use the mic to be a voice to the voiceless.” “Oh My” starts with an Obama sample that includes a patriotic call for unity, then launches into Noah-O’s cutting flow about the recent state of America with lyrics that touch on poverty, education, the Iraq War and welfare. This is working-class hip-hop buoyed by a catchy, ’70s-styled chorus sung by guest artist and producer Mikki Kawane. How many rap songs talk about being responsible financially, or examine the cost of living? “Oh My” will be featured on Noah-O’s debut album, “Struggle Muzik.” noah-o.com.