Music emotion recognition is an industrial and academic challenge. While we observe an explosion of multimedia content, it becomes crucial to build structured sets of terms and concepts so as to help knowledge organization. In music libraries, sentiment analysis and emotion classification are emerging and remain a subject of ambitious research. In this chapter, we will do an overview of the state-of-the-art over the application context and the quantitative and qualitative assessment of feelings through the intersubjectivity of the subject. Then, as part of our PhD works at the laboratory GERiiCO - university Charles de Gaulle Lille 3, we will present our experimental protocol for evaluating the intersubjectivity of the subject and the first results obtained so far.