Not at all unusual. Western culture has always had a way of taking native things and running away with spoils.

The French invaded England in 1066 and and basically uprooted anything that defined the 'Angles' influence in said country.

The Spanish and Portugese started exploring the new world and set off a wave of Native disenfranchisement that persists to this day.

Country music owes much of its early success to charlatans and grifters who combed the hills and backwoods of Appalachia for catchy tunes written by marginalized Black people, who then reworked them into hits for a more easily digestible pool of White performers.

And it has to be said that the American music scene from the late 50s onward was basically built on the backs of British acts - The Beatles, Black Sabbath, Led Zeppelin, Eric Clapton, plus countless others.

We just have a fascination with all things foreign and have a way of trying to define our social worth by how many of these things we appropriate...apart from equity for marginalized people anyway...

That's probably why the Wayne Newton song you mentioned went with a German title instead of the original English. Foreign words give the appearance of cultural sophistication, usually where none actually exists...

Thankfully a reverse trend is now occurring. The Blues and Jazz, being distinct Black American musical inventions, now have admirers and devotees on pretty much every continent. Hopefully that helps pioneers like Robert Johnson and Billie Holiday dance in their graves, instead of rolling over in them...