Sparham on Family Tree Circles

I am the 5 x great grandaughter of Johann Andre he lived in Offenbach. He was a composer of opera and light music and Keppelmeister to the King of Prussia. I believe that he is a relative of Major John Andre. It is mentioned in Robert McConnell Hatch's book "Major John Andre, a Gallant in Spy's clothing" visited his relative Johann Andre in Offenbach. I cannot find the connection, there is not much info about John's parents that can lead me any further in my search. I would be grateful if anyone can help.