A Murderous Affair in Horizon Tower Episode 11

Yang and Zhong go to speak with Yan Jun. Ah Jun was a musical genius and ever since they were young, he could play any piece on the piano by listening to it. They used to dress him as a girl so he could pretend to be their friend playing the piano in order to get some money. Officer Yang tries to convince Yan Jun to report his father and he gets upset. His manager files a complaint against Yang. Detective Zhong and Yang visit Mei Bao and Ah Jun's school instead and through them find Mr. Song who in the past, had given his piano to the kids. He told them that their father was a scum who beat them up all the time. Just then Yan Jun calls Yang. (Source: Autumn carrot at MyDramaList)