1. Introduction

    1. Some background

    2. Questions emerged during 2018

  2. What could be the basic principles of harmony?

    1. Icosahedral harmonies

    2. Why quints are near to each other harmonically?

    3. What could be the rules for building a harmony?

    4. More general notion of harmony

  3. Harmony and biology

    1. Could harmonic principles be realized in biology?

    2. Could biology help in the understanding of musical harmony?

    3. About the interpretation of bioharmonies

  4. Icosahedral harmonies

    1. About symmetries of the icosahedral harmonies

    2. Summary of the basic results

    3. Tables of basic 3-chords for the icosahedral harmonies with symmetries

  5. New results related to the notion of bio-harmony

    1. Summary of the background

    2. Some questions about the realization of the bio-harmony

    3. Some questions about the realization of the bio-harmony

    4. Can one imagine a modification of bio-harmony?

    5. Icosa-tetrahedral and icosa-dodecahedral bioharmonies as candidates for genetic code

  6. Appendix

    1. Chord tables for some harmonies and their inverses

    2. Calculation of incidence matrices

    3. Simulation of harmonic DNA sequence

    4. Illustrations of icosahedral Hamiltonian cycles with symmetries