Complex sentence: Directed by his mother, Usher joined the local church youth choir in Chattanooga, when he was nine years old; there, his grandmother discovered his ability to sing, although it was not until Usher joined a singing group that she considered he could sing professionally.
Split into simpler sentences: Directed by his mother, Usher joined the local church youth choir in Chattanooga, when he was nine years old. There, his grandmother discovered his ability to sing, although it was not until Usher joined a singing group that she considered he could sing professionally.