An apparatus for analyzing music based on sound information of instruments is provided. The apparatus uses sound information of instruments or the sound information and score information in order to analyze digital sounds. The sound information of instruments performed to generate digital sounds is previously stored by pitches and strengths so that monophonic notes and polyphonic notes performed by the instruments can be easily analyzed. In addition, by using the sound information, of instruments and score information together, input digital sounds can be accurately analyzed and can be detected in the form of quantitative data.