Musa

Musa is another main protagonist from the Winx Club. She is the Fairy of Music and is from a world named Melody (Harmonic Nebula in the 4Kids dub)

Ultimate Story
Musa was one of the chosen Winx fairies of a group known as the Celestial Winx, chosen subordinates of the Great Wizard. They were tasked to defeat an evil entity known as Malicet before he destroys the Universe. She and her friends had shown to stand a match against Malicet and have fought against him almost endlessly.

However, something went horribly wrong during their final battle against him and he nearly destroyed them. Knowing that they can defeat Malicet, they sacrificed themselves to seal him away and disappeared without being seen or heard from again.

4000 years later, she and her friends appeared in a dream Fox had during a deep sleep. They revealed to him that they are still very much alive and that their powers are what's keeping Malicet sealed away in his prison. However, they are slowly regaining their powers and although they will be able to manifest their very beings, this also means that the seal to Malicet's prison is weakening and he will be free. Knowing this, Fox and his friends motivated the new Celestial Winx to finish up their training so that they will be ready to defeat Malicet when he has successful broke out of his prison.