IT IS A WELL KNOWN FACT THAT THE BRAIN is divided into two distinct hemispheres and that each side has separate cognitive and imaginative tasks. This has led to many misconceptions about how the brain works. This article will try to clarify a few points about the hemispheres and misconceptions about them.

In the 17th century, Rene Descartes correctly postulated that the entire human brain must work together in order to properly function. Unfortunately, Descartes' pioneering theory began to lose credence in the 1860s and 1870s. Studies involving brain damage yielded results that seemed to point out extreme differences in how the two halves of the brain function. This led to many misapprehensions about the brain , and how the hemispheres relate (Levy, 1985).
The truth of the matter is that the hemispheres work together for almost every task. The specialties that each side possesses makes it easier for both sides to work together.
The following graphic illustrates the differences between the hemispheres. Complicated, isn't it? The hemispheres' specialties are a lot more convoluted than the mistaken idea that the left controls logic and the right controls creativity. 

Figure 1. Brain hemispheres and their functions (Jensen, 1996 p.20).

Music is a subject that has long been mistakenly attributed only to the right hemisphere. Actually, the right hemisphere mainly has to do with the enjoyment of music. Analyzing a musical piece's structure is done by the left hemisphere (Sprenger, 1999, p.42).
For musicians, music is mainly a left hemisphere process and for non-musicians it's a right brain process (Jensen, 1996, p.20). Both hemispheres still work together, but one can take charge depending on the situation.
In fact, the composer Ravel, suffered a debilitating stroke which damaged the left side of his brain. He was never able to compose again. If creativity was controlled strictly by the right, this would not have happened.

Figure 3. The corpus callosum

The corpus callosum is the only structure in the brain that connects the two hemispheres. If it were to be severed, your hemispheres would not be able to communicate any longer. A lot of the research about the two hemispheres was done on people whose corpus callosum was severed.

This article has only touched briefly on the truth about the two hemispheres, what makes them similar and what makes the different. If nothing else, I hope that this article helps demonstrate that the brain is a marvelously complex organ that its function cannot be quickly and easily pigeonholed.

 Shawn Aeria, 2001