Complex sentence: Kehlani was a dancer until an injury called "jumpers knee" forced her to focus her artistic talents elsewhere, which is when she discovered singing, & before the injury she studied dance at the Oakland School for the Arts.
Split into simpler sentences: Kehlani was a dancer until an injury called "jumpers knee" forced her to focus her artistic talents elsewhere, which is when she discovered singing. Before the injury she studied dance at the Oakland School for the Arts.