Frankie Presto is an orphan raised by a blind music teacher in a small Spanish town. At the age of nine, his guardian sends him to the USA, taking only an old guitar and six precious strings with him. Frankie quickly finds his footing in the new country and soon becomes a respected and admired part of the 20th-century music scene, spanning from classical to jazz to rock 'n' roll. He meets and influences many, including Hank Williams, Elvis, Carole King, Wynton Marsalis, KISS, and many other music legends in various ways. Eventually, he becomes a star himself, records his own albums, and is adored by fans. However, his talent becomes a burden when he realizes that he can change people's lives through his music. For every time a string on his guitar glows blue, he has impacted someone's life.