He lived most of his childhood at his grandparents in Riga, where his grandfather, Paul Nelder, owned a music supply store at the current location of the Freedom Square.
Working at his grandfather's business, Erhardt entered the stage as a cabaret artist in several Riga coffeehouses, and in 1937 even appeared on the German RRG radio.
[5] The spectacle wearer and non-swimmer Erhardt was drafted into the German Kriegsmarine navy during World War II, but only on the third call-up; he served as a pianist in the Marine orchestra and only handled weapons during his basic training.
Still today, many family gatherings which include the older generation tend to end in spontaneous recitations of Erhardt's most famous pieces such as Die Made.
As a belated 70th birthday gift, he was awarded the Commander's Cross of the Order of Merit of the Federal Republic of Germany four days before his death in 1979.