This book is about the human mental capacities that are mostly veiled in the use of language yet can be revealed through music activities. In speech, just one word is articulated at the time, whereas in music different pitches sound simultaneously. This conflict demonstrates that rationality must be regarded as relative, as rationality in music may create chaos in speech. Moreover, investigating the role of sound in synesthesia reveals that its aesthetic combinations are related to the human capacity to enjoy different types of harmonies in music. Drawing on new research regarding synesthesia as a more fundamental basis for human cognition, this book brings this a step further by introducing synesthesia as a general metacognitive process, hinting at the aesthetical origin of fundamental logical operations. Bringing together a number of cultural perspectives on music, language, and mathematics, this volume expertly illustrates that music reveals a fundamental system that deeply combines the sensorial and the intellectual human capacities.

Chapter 1. Introduction.- Chapter 2. The Understanding of Music in Early Psychology and Musicology.- Chapter 3. The Experimental Psychology's Use of Music to Uncover Mental Capabilities.- Chapter 4. Polyphony as a Higher Mental Function.- Chapter 5. A Psychological Approach to Complexity: Synesthesia.- Chapter 6. Sound and Communication.- Chapter 7. Systems and Complexity.- Chapter 8. Musical Systems.- Chapter 9. Music in Literature.- Chapter 10. From Synesthesia to Metacognition./