This is already old news about MBD, like most Jewish singers, taking non-Jewish music, practically note by note, and making it Jewish. Yes, in Chassidic circles it’s not assimilation when taking a piece of Goyish music and making it Jewish, as all music (supposedly) came from the Jews in the Beis HaMikdash and we’re taking back what’s rightfully ours, (whatever), restoring it to it’s old spiritual glory, but stealing is stealing. Here are some related videos:
The famous Yidden Yidden:
The Original German song “Dschinghis Khan,” in 1979
A Japanese remake by Berryz Koubou:
There used to be a “Dschinghis Cohen” clip, where a Jew dressed up as Dschinghis Khan at a Chasunah and made fun of the song, but that clip is no longer on YouTube.
Here’s the link to download  the Dschinghis Khan clip:
In all, “Yidden” comes from the composer Mordechai ben David who has gone to Jewish schools to talk about the evils of non-Jewish music.
If he really believed that then it’s a real wonder that he somehow got the music of Dschinghis Khan, a German pop group from 1979.