This book describes an active integration of mathematics and music applied to improve senior secondary mathematics students' understanding of the concept of function by considering nine author-developed analogies. The book presents musical analogies related to different aspects of function, that can be used to teach secondary students to pass from traditional algebraic, graphical, and tabular representations of functions to musical representation. Students' existing mathematical knowledge is not contradicted or confused but, on the contrary, it is empowered and expanded through their general human musical intelligence. The findings suggest that the application of these nine author-developed analogies between mathematics and music makes a statistically significant improvement in students' understanding of function. The presented approach is highly flexible and can be adapted and used in any secondary school. The book has potential significance for mathematics teachers, researchers, and learners, who (regardless of their music education background) can apply this mode of active integration of mathematics and music successfully.