Far away, in a land of music and magic, live two beautiful girls. Liana and Alexa are best friends who share everything-especially their love of singing. One day, while walking through the forest, the girls find a magical mirror. As they clean the mirror and sing, something amazing happens! A girl named Melody appears in the mirror's surface. Melody tells the girls about the secret of the Diamond Castle. The Diamond Castle, Melody explains, is the home of all music, where three musical muses once resided-until one evil muse, Lydia, tried to take the castle for herself. In an act of safekeeping the other two muses entrusted the key of the Diamond Castle to Melody. And to keep the key safe from Lydia, Melody hid herself in the mirror. But now she can't get out. She needs Liana's and Alexa's help to free her from the mirror and to save the Diamond Castle. The two girls begin a journey that will take them far away from their homes. Along their way they make new friends-and foes. But will the power of friendship prevail?