A fact from Erfreue dich, Himmel, erfreue dich, Erde appeared on Wikipedia's Main Page in the Did you know column on 26 December 2020 (check views). The text of the entry was as follows:
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To expand on my DYK comments, I am unclear what "the beginning of Christian hymns in German" means in this context. Possibilities that come to mind are it being part of the song in the beginning of each hymn, the first hymn in a hymnal service, or perhaps the first German Christian hymn. (Not knowing precisely what a Psalmlied is probably isn't helping me.)
My understanding is that the words "Erfreue dich, Himmel, erfreue dich, Erde" make up the first line of the 1697 and 1963 hymns, but also serve as the name of those hymns, so I think another point of confusion is not understanding whether their use refers to the words themselves ("first line" as mentioned in the DYK), or to the hymn(s) as a whole.
A couple of other points, the way "Without going into detail about the nativity" is written is a bit ambiguous as to whether it means the song is not going into detail, or the Wikipedia article is not going into detail. Also missing is a note as to whether the Christmas Carol version is still sung, or if this song is now used only in the Psalmlied form.
It's common to name hymns by their first line, - there a only few excepteions. Sorry for the sloppy "beginning". The song is not going into detail, - can you word that better. I never heard the Christmas carol sung, but am no good source ;) --Gerda Arendt (talk) 18:01, 1 December 2020 (UTC)[reply]
Thank you for asking. I think matching sources is not the only thing to be considered. "is the name given to two related Christian hymns in German which begin with those words", - no, hymns are not "given names", they are usually referred to by their first line. Otherwise it reads fine to me, thank you. I tried also now to clarify some, please check. --Gerda Arendt (talk) 15:00, 4 December 2020 (UTC)[reply]
Could follow that structure and list them one after the other then: "is a Christmas Carol that was later modified into a Psalmlied", with appropriate tweaks in the succeeding sentences to remove redundancy. CMD (talk) 15:59, 4 December 2020 (UTC)[reply]
It might be easier to select one song as the 'main topic' of the article (otherwise, for example, the infobox will not work). The content would be the same, just the framing would shift. Per the infobox and that you've never heard the carol, the Psalmiad may be the primary topic. CMD (talk) 17:31, 4 December 2020 (UTC)[reply]
"Erfreue dich, Himmel, erfreue dich, Erde" (Be glad, Heaven, be glad, Earth) is a German Psalmiad (psalm song) based upon Psalm 148. It was created by adapting a short Christmas carol which was written down in the late 17th century. This carol was expanded by Maria Luise Thurmair into the modern Psalmlied 1963, and became part of modern German hymnals and song books."