The raison d'etre for copyright protection is to balance the conflicting interests of the public and the private. The public wants access to the work, while the private needs to be compensated for the time, skill and labour expended for the work. The balancing of the interests requires keeping a pool free for all to exploit. Copyright law ensures this pool by keeping ideas free for all to exploit. Copyright does not protect ideas, but only expression of ideas. The difficulty in preserving this balance is to draw the line between idea and expression. In music the divide is more blurred due to the availability of limited notes and ideas. The basic concept of idea is explained by studying the theories of Plato, Locke and other philosophers.  Further ahead the researcher identifies the difficulties in drawing the dividing line between idea and expression and also analyses the need for sieving out the protectable from unprotectable elements in music. Differentiating between idea and expression is pivotal  in copyright law as only expression of an idea is entitled to copyright protection. This study attempts to discuss the difficulties encountered by music due to the idea expression blur.