Singing has existed since the earliest beginnings of music, and is still developed and studied today. The goal of singing involves teaching children a certain number of songs and developing their voices. Lyrics are considered a significant factor in any children's song, and they must be age-appropriate. Songs may be classified based on their origin (folk, artistic, and popular and entertaining songs), the content (lyrics), and their functional purpose. Based on the content, songs may be classified as occasional or didactic and functional. Songs that are sung on special occasions, such as holidays and season changes, are referred to as occasional children's songs. This thesis illustrates the possibility for the integration of two school subjects - Music and Nature and Society using children's songs found in the textbooks. The analysis of the songs taught in the first three grades of primary school is based on the song contents and topics. The objective of the analysis was to determine which songs may be integrated with the contents taught in the subject Nature and Society. Contemporary textbooks for the first three grades of primary school, published by Školska knjiga, Profil Klett, and Alfa were analysed. The topics covered in the subject Nature and Society are seasons, transportation and traffic, my neighbourhood, living nature and holidays. For each grade, the previously mentioned thematic groupings were examined independently. The study revealed inconsistencies in the textbooks by different publishers used in the same grades. The most noticeable difference is related to the topic transportation and traffic, which is important for first and second grade students' everyday movement, and for which there are no songs in the first and second grade textbooks published by Školska knjiga. Other publishers have fewer songs regarding transportation and traffic than those about other topics such as seasons or holidays. There are no significant differences in the number of songs by grade or publisher related to other topics. That is, there is a similar number of songs for each of the following topics: seasons, my community, living nature and holidays.