Ruby is so loud, she drives everyone around her crazy. When her teacher suggests that Ruby could turn down the volume, like a sound-blaster, Ruby turns it up instead - and drives away all her schoolfriends. Ruby feels really blue - until Bernard and Zelda, the saxophonist and blues singer living in the basement, offer to give her singing lessons. Not only does Ruby learn to be quieter, but she also learns to sing everything from the sharp, zooming sounds of the city to gentle, breathy notes like an evening breeze, but most of all she learns to sing with feeling - and on the day of the school concert, she's awesome!