What does "mit Musik" mean?
It is the traditional marinade of onions, vinegar and oil with pepper and salt. German Wikipedia says the name allegedly hints at the noises onions cause in digestion, and gives a second theory about vinegar and oil bottles once clinking when served.
Is Handkäse protected?
Only the name Hessischer Handkäse, registered as a PGI by Commission Regulation (EU) 784/2010. Since September 2010 only sour-milk cheese made and packed in Hesse may carry it, though the quark need not come from Hesse. Handkäse as a type is not protected.
What do people drink with it?
German Wikipedia says cider is the usual drink with Handkäse, but that in some areas such as Rheinhessen and the Palatinate a dry white wine is drunk with it as well.
Is Mainzer Käse the same as Handkäse?
Close, and the names overlap: in Mainz and the Rhine-Main area Mainzer Käse is simply called Handkäs. Both are small sour-milk cheeses of low-fat quark, but German Wikipedia notes that Handkäse can also be made as a white-mould cheese, which Mainzer Käse is not.
Where does it come from?
From Groß-Gerau in Hesse, across the Rhine from Mainz. German Wikipedia says it was created there in 1813 and sold at the Mainz market, and Käserei Horst's company history dates the area's cheese-making to the same year.
How is it served in Mainz?
Often as Handkäs mit Musik, marinated in vinegar, wine, oil and onions, and offered with or without caraway.
What is in Spundekäs?
In the basic recipe, two parts cream cheese and three parts cream quark, pepper, salt and sweet paprika, with onions served over or beside it. Many cooks add butter, egg yolk, Schmand or crème fraîche.
What is it eaten with?
Salt or lye pretzels as a dip, or hearty bread as a spread, according to German Wikipedia; rheinhessen.de says dry bread or salted baked goods, especially lye pretzels.