Lee Ji Hoon revealed why Ock Joo Hyun called him into her dressing room on 'Knowing Brothers'.

On the August 3rd installment of 'Knowing Brothers', Lee Ji Hoon revealed, "When Ock Joo Hyun and I did a project together, I got nervous whenever she sent me a text message saying, 'Come to my room.'" He continued, "Before we started the show, I always practice projecting. I start warming up my throat first. Ock Joo Hyun arrived next door, heard my voice, and if she thinks, 'We can't go on like this,' she sends me a message that says, 'Come to my room.'" 

He added, "When I go, she teaches me how to project step by step. At first, she helps me open up my chest and diaphragm. If it still seems closed, I yawn. If my pitch still doesn't go up, she pulls the hair on the back of my head. That really helps. If you sing high notes, your body moves forward, but Joo Hyun's style is standing straight up and letting the sound ride into the microphone. During our first rehearsal, I didn't know that, and there's a part where I hug her as I sing. We were singing to each other, and she knew I wouldn't project as much if I bent over so she held my back for me."

Watch Lee Ji Hoon and Heechul re-enact the scene in the clip above!