The Baumgartens from somewhere in Germany

Quite some time ago I found out the names of the siblings of my 5x great grandfather the bassoonist Samuel Christian Frederic Baumgarten, according to the will of their brother John Henry Baumgarten. Although both Samuel and John lived and died in England, it has long been believed that Samuel was of German birth (according to musical history sources), but no one knew exactly where he was from. Once I knew names of Samuel and John's brothers and sisters I hoped that information might help me narrow down where the Baumgartens came from. The names were Leopold Baumgarten, Frederick Baumgarten, Gertrud Schwein, Magdalen Schmied, Julia Haberkorn, and Frances Baumgarten.

My best hope was FamilySearch, so I plugged all the names into FamilySearch, focusing particularly on the married sisters - this was because I had an extra name to work with - not just the maiden name but also the married name. I possibly found something with Julia Haberkorn - a marriage record for a Juliana Ernestina Baumgarter to a Johann Friedrich Haberkor in a protestant church in Lahr, Offenburg, Baden, Germany on 17 February 1757. Despite the slightly different spellings I thought it was enough to order the microfilm of the parish records for Lahr in to my local LDS Family History Centre.

The microfilm arrived this week and I was able to make the time to have a look. I found February 1757 and looked for the names Baumgarten and Haberkorn. I was confused to find an entry for Christian Leopold Baumgarten rather than Juliana Ernestina Baumgarter/n. But she was there as well, only her brother Christian Leopold was married ten days before her.

Going back to Juliana though - in the parish records her surname was actually Baumgarten, not Baumgarter, and Haberkor was actually Haberkorn - they have evidently been transcribed incorrectly by the FamilySearch transcription volunteers. Although I haven't quite worked out exactly what the entry says (it's written in German language in the German Kurrent script), it does tell me that Juliana's father's name was Nicolaus Baumgarten, and seems to suggest that both he and the groom - who was a widower - were possibly secondary teachers (Praeceptoris secundari)?

The entry for Christian Leopold Baumgarten's marriage to Maria Salome Dieterlin on 7 February 1757 shows that his father was Joh. Nicolaus Baumgarten, with the same occupation as Juliana's father. I'm pretty sure that means they were one and the same father. Interestingly, if I'm translating it correctly, it suggests that the father Johann(es?) Nicolaus Baumgarten was from Usingen (...Joh. Nicolaus Baumgarten Cantoris und Praeceptoris zu Usingen...).

So the question is: are Juliana Ernestina Baumgarten and Christian Leopold Baumgarten siblings of Samuel and John Baumgarten?

• Names: Julia could well be a diminutive form of Juliana, and with the baptisms of his children Christian Leopold was sometimes named as Leopold Christian.
• Church: that they were married in a Protestant church rather than a Catholic church fits well with the fact that Samuel Baumgarten's children were baptised in a parish of the Church of England.
• Usingen: if Johann(es) Nicholas Baumgarten was from Usingen that gives me a link to Samuel Baumgarten's daughter Marie, who was, according to the Burgerbuch of the city of Mulhouse, from Nassau-Usingen. As far as I know, none of Samuel Baumgarten's other children were born there, so what were they doing there if they weren't visiting family? It is possible he could have been on a music tour, but there is little evidence that he did anything like that - apparently only being well known as a musician in England. And would you take your apparently heavily pregnant wife with you on a music tour anyway?

So if these are Julia Haberkorn and Leopold Baumgarten, sister and brother of Samuel and John Baumgarten, where are the rest of the siblings? I haven't seen the baptism and burial records for Lahr to see if the Baumgarten siblings were born/baptised in Lahr, or if their father/parents was/were buried there. That may be my next step. And I also need to investigate the Usingen link and see where that takes me. So the circumstantial evidence points to them possibly being the siblings of Samuel and John, but there is nothing at this stage that indisputably links them. More work needed!