One of the best Indonesian children’s films, distinguished by not being a fairytale as other films popular at the time, My Harmonica combines humour, mischief and naivety. Sani is an orphan who is raised by his grandmother in the village. His parents died when he was little. His teachers think that he can develop further if he goes to Jakarta to study. Reluctantly, Sani agrees. So in Jakarta, he stays with the younger sibling of his teacher, but he faces problems. The most intriguing part is his wish to have a harmonica, a new instrument that he has never seen before.

Anna is a private tutor for Frans' two children who have just lost their mother. The mistress of the house died from being poisoned by Renita, her own younger sister. There she was seduced by Danny, Frans' brother-in-law who she initially rejected. However, love began to grow when Danny moved to Jakarta. Unfortunately, their letters were hijacked by Renita. Then there was also a declaration of love from Frans who eventually also died from Renita's poison.

Bung and Mas are two caretakers in an orphanage at the outskirts of the city. One night, Bung and Mas find a baby abandoned at their front yard. They have a dilemma: if they take it, they are afraid of being scolded by the head of the orphanage, Mr. Sastro; if they do not take it, it is against their conscience and profession. So they take the baby, and are relieved that he is well accepted by Mrs. Sastra and the children in the orphanage. Then Bung and Mas have an altercation with some thugs who chase them, and a car hits them so they end up in the hospital. But in the end, the children they care for are the ones who protect them.