Speak up or shut up”, says the back of the T-shirt of a teenage boy standing in front of me. He is surrounded by his friends, their arms around each other’s shoulders as they bob their heads along to the music. All around me, their phones in their hands, are more boys and girls of the same age. Most of them wear baseball caps, trainers, jeans and oversized jumpers.Some wear surgical masks, revealing little more than their eyes. Above them all, on a stage backdropped by low-budget graphics that flash relentlessly, stands a youth with a microphone. His tattooed torso is stripped bare, his right foot planted on a speaker as if it were the head of a defeated foe. “Put your middle fingers up!” he roars.

This festival — an all-day hip-hop concert at CentralWorld, one of Bangkok’s largest shopping centres — is in celebration of Never Say Cutz, a chain of barbers owned by DaBoyWay, a member of Thailand’s most successful hip-hop group, Thaitanium. It’s been nearly two decades since the band shot to fame, but Thaitanium is still enormously popular in Thailand. The concert will end with all three members taking the stage together, but first we have this: nearly six hours of up-and-coming young rappers as the opening act.

Thailand’s hip-hop scene has attracted attention lately owing to the notoriety of Prathet Ku Mee (“My Country’s Got”), a scathing diss track aimed at the country’s military government by Rap Against Dictatorship — a group comprising largely of seasoned underground rappers in their thirties. But as I stand here, surrounded by swaying teenagers while having my ears assaulted by monotonous beats, I am reminded of how different mainstream Thai hip-hop is from carefully crafted rhymes about political oppression and social ills. These young male rappers, mostly in their late teens or early twenties, might be raging like Rap Against Dictatorship, but they are doing it in a different way.

• Tags: Issue 14, Klong Toey, Pim Wangtechawat, Thailand