1. Introduction; 2. Experimental heat capacity; 3. Excitations in solids and gases; 4. Energy and heat capacity of solids; 5. First-principles description of liquids: exponential complexity; 6. Liquid energy and heat capacity from interactions and correlation functions; 7. Frenkel theory and Frenkel book; 8.

Collective excitations in liquids post-Frenkel; 9. Molecular dynamics simulations; 10. Liquid energy and heat capacity in the liquid theory based on collective excitations; 11. Quantum liquids: excitations and thermodynamic properties; 12. Sui Generis; 13. Connection between phonons and liquid thermodynamics: a historical survey; 14. The supercritical state; 15. Minimal quantum viscosity from fundamental physical constants; 16.

Viscous liquids; 17. A short note on theory; 18. Excitations and thermodynamics in other disordered media: spin waves and spin glass systems; 19. Evolution of excitations in strongly-coupled systems; References; Index.