Abraham Liscov adopts the title character and teaches music to Johannes Kreisler in another work by this man.  
In one work by this man, one character buys old violins, plays them once, and promptly takes them apart and is devastated by the death of his daughter Antonie, and in another, the title character solves a mystery regarding a goldsmith who is so obsessed with his creations that he murders his customers to get them back, Cardillac.  Abraham Liscov adopts the title character and teaches music to Johannes Kreisler in another work by this man.  In addition to Councillor Krespel, Mademoiselle de Scudery, and The Life and Opinions of Kater Murr, he wrote a story in which Nathanael jumps from the tower of city hall after Lothar saves his fiancÃ©e Clara from him and a novel in which Count Victorin and Medardus partake of the titular beverage.  FTP, name this German author of The Sandman, The Serapion Brethren, and The Devil's Elixir.
In one work by this man, one character buys old violins, plays them once, and promptly takes them apart and is devastated by the death of his daughter Antonie, and in another, the title character solves a mystery regarding a goldsmith who is so obsessed with his creations that he murders his customers to get them back, Cardillac.  
E. T. A. Hoffmann