“Radius FG” is a new digitisation of the Art Nouveau hot-metal font “Radium”, published in 1905 by the German typefoundry Ludwig & Mayer.
It became again popular in the 1970s after Hubertus Carl “Hace” Frey had reworked the bold weight under the new name “Charleston”. It is mainly found as a display typeface on period musical album covers.
This version comes again with a regular and bold weight, both with extensive latin character sets for most Western and Eastern European languages, available under the SIL Open Font License. For details see https://scripts.sil.org/OFL

Donations can be made via the dafont.com paypal link of the font. 

There is also an extended with version of the bold weight under the name of “Lutherkirche FG”.