Accessible in the context of music means that a piece can be easily appreciated and enjoyed by many people. The degree of accessibility can vary greatly among compositions, and it can also vary for a particular composition according to such things as the level of music experience, music education and cultural background of the listener. Music that has a simple melody, especially one that is hummable and easily remembered, is usually much more accessible than music that has a difficult-to-discern melody or no melody, such as some atonal music and especially pieces composed using serialism techniques.