The core activity of Jean-Claude Bossel Créations Sàrl encompasses four main areas: 1. **Art (Painting)**: The production of original paintings and thematic series. 2. **Music (Music)**: The composition of original scores for concerts or fictional works. 3. **Mathematics (Mathematics)**: The creation of textbooks for mathematics education. 4. **Creative Project Management (Reality and Fiction)**: The development of a fictional story and two real brands. Thus, the company combines artistic, musical, mathematical, and creative activities under one roof.