Accidentals are notes outside of a scale, and a scale is an arbitrary concept chosen by some ancient people who decided certain notes sound good together. http

Accidentals are notes outside of a scale, and a scale is an arbitrary concept chosen by some ancient people who decided certain notes sound good together. http://en.wikipedia.org/wiki/Accidental_%28music%29 http://en.wikipedia.org/wiki/Accidental_%28music%29