Jasmine is eight years old and a musical virtuoso. After the death of her parents, who were also musicians, she experiences a rollercoaster of emotions. As she tries to navigate her sadness, rage and fear, she also starts to notice that something strange is happening to music. Hidden inside a chest that belonged to her parents, she finds a mysterious musical score. As she stares at the sheet music in wonder, Jasmine is sucked up by a tuba and transported to Soundland, a secret, musical paradise.
There, she meets the guardian of the land, Jambo, who is going through an age-related crisis that is making him very depressed. Even so, Jasmine manages to get him to tell her three secrets that will mark the beginning of a magical journey for both of them.
And so starts an adventure across land, sea and air to save music. Joining them will be lots of other musical inhabitants of Soundland, as they embark on a journey that will see Jasmine letting go of her emotions and slowly coming to terms with her grief, while Jambo finally learns to accept himself for who he is. As they continue on their quest to find the missing half of the score, a beautiful friendship will blossom between the two, that will unite them forever.