Hong Kong crime movie from 1975

The blind Yip Man-chiu was abandoned at birth. Following the death of his foster parents, the boy is sold by his uncle Ah Sam to a blind Taoist priest, an abusive man. Running away from home, Yip is hit by a car and sent to a school for the blind by the social security workers. His talents impress the musician Siu Kwong and wins him a place in a music school for the blind. There he is joined by fellow students Lung Kwok-kei, a runaway child with an abusive stepmother, Chow Kuen, an abandoned child found on a train, and Cheung Kin-ching, an avid music lover sent to the school by her loving well-to-do father. The four children blossom into accomplished musicians under the tutelage of Siu and his wife and together with the less fortunate others, form an orchestra which earns a reputation for excellence.

'Agent Number Two' Lee Kwok-wai of the resistance troops Red Rattlesnake sets off for Guangzhou to assist Agent Number One in rescuing their comrade Pang Yau-lan from the puppet army. Lee approaches his former lover Lam Ying-tsi, the mistress and trusted aide of the puppet commander Wong Tai-wai, who has fallen prey to the lip service of the beautiful and smart songstress Pak Lai. Following the vandalism of the arsenal, Pak is quick to point the finger of blame at a spy at work. Lam combs their home for clues and finds Lee's recording devices. Furnishing Lee with misleading information, Lam has Lee and associates arrested. Pak appears to their rescue, revealing herself as Agent Number One. The dauntless spy sabotages the enemy's ammunition and communication network, captures the commander before joining her comrades to celebrate a successful withdrawal. (Synopsis based on audiovisual materials)

Yu Kwok-Kei cannot pay his debts and disguises himself as Ma Ka-Wai, his cousin Yu Lan-Fun's fiancee. He tries to kill Lan-Fun. A fisherman saves Fun. She believes that Ka-Wai was the attacker, but she can't understand why. After Fun has been missing, her family puts an announcement in the paper. Meanwhile, Chan Lan-Fong, who just comes to Hong Kong, looks like Fun and is brought to Yu's home. Fong's habits are totally different from Fun's, and she cannot recognise the family, who thinks Fun has amnesia. Fun knows that her family has mistaken somebody else for her, so she goes back home secretly and teaches Fong her habits and customs. Fong does what Fun tells her, and the family thinks that she has recovered. Kwok-Kei has a guilty conscience, so he disguises as Ka-Wai again, intending to kill Fun/Fong. But he fails and got arrested. Everybody learns that Kwok-Kei wanted to kill Fun. Moreover, Fun's mother discovers that Fong is Fun's lost twin sister and the family is reunited.