planet4d->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 toPlanet4D 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