planet4dPlanet4D is mainly based on Hyperspherical Models, Other Contributions are dedicated to Flat Networks. Very fast presentation of my 4D Models for Mathemusic. in 2020 Planet 4D models->Some isometries in the Tonnetz discovered by G. Mazzola and formalized in the 4D space by Emmanuel.Amiot and Guillaume Baxias.->Hypersphere of Tonnetze, is a graphical illustration of the work initiated by Louis Bo to