Kaerazaru Hyouga

Taken from Stage Storm:

Eleanor is the daughter of the king and a opera singer. Some assasins are sent to kill them due to the scandal so her mother made her promise to leave the country forever before dying. She tries to survive in the streets singing the songs her mother taught her. She befriends Johan, an acordeon player and they travel around various places while singing together. The queen orders some assasins to kill a girl by mistake in Eleanor's Nursing Home. She joins a group of gypsies and is discovered by Alex Lee, a famous manager. Thanks to him he makes her debut as a singer by the name of Odette Lauryn. She becomes a worldwide, popular singer, so she gets to act in her hometown in front of the king.