The right hemisphere is the ‘creative’ brain and the left hemisphere is the ‘logical brain’.
The 2 sides of the brain do have different strengths. The right side is better at emotion, visual & spatial tasks, and getting the ‘big picture’. The left side is better at basic language (words & sentences) and sequencing. But they interact constantly, so everything we do is a result of the 2 sides of the brain working together.
The ‘creative brain’ idea likely came from the fact that artists and musicians are more often left-handed than the general population. Since the right side of the brain controls the left side of the body, it was concluded that the creative, artistry was controlled by the right side of the brain. Some aspects of artistry and music do rely on seeing the ‘big picture’ and require visuospatial skills, but other aspects are very logical (e.g., music is mathematical) and sequential, which is more like the strengths of the left hemisphere.