Among the great violinists, Niccolo Paganini was the pre-eminent collector of violins. He owned nineteen stringed instruments at the time of his death: two violas, four cellos, and thirteen violins, among them seven Stradivari violins. Other violinists may have had as many as two or three Strads during their careers. A few, like Louis Spohr or Fritz Kreisler, reached five. Joachim surpassed this number significantly. However, he did not assemble many instruments at one time; he bought and sold.

Joachim often lent his fiddles to his best students. For instance, he lent a Strad to Karl Halir (Karel Halíř) for a United States tour. He lent his 1723 Stradivari to Enrique Arbós, and he lent Geraldine Morgan the 1708 Stradivari (“Morgan”), which he later sold to her. Joachim donated six extraordinary musical instruments to the collection of the Staatliche Hochschule für Musik in Berlin. Unfortunately, five of them were lost during World War II.

In his biography of Joseph Joachim, Andreas Moser tells little—almost nothing—about which violins Joachim owned or played. Likewise, Beatrix Borchard's voluminous book on Joseph Joachim is replete with footnotes and references, but not to his violins. Other writers, such as Günther Weiß, who wrote the biography of Henri Marteau, Joseph Joachim's successor at the Berlin Hochschule, have similarly not been interested in the violins that their subjects played. Why do musicologists neglect the importance of the instrument to the violinist's art?

We learn from Albert Mell's essay “Joseph Joachim, a Connoisseur of Fine Violins” that Joachim, like other celebrated violinists up to the present day, preferred the violins of Antonio Stradivari. Ernest N. Doring, in his book How Many Strads?, lists nearly all the Stradivari violins that belonged to Joachim or have been attributed to his ownership. One also can find articles on the Internet that list the famous violins that passed through Joachim's hands. An English Wikipedia article mentioned twenty-six before the end of 2016; Cozio describes nineteen violins and two violas for Joachim. It lies beyond the scope of this chapter to give a complete survey of all of Joachim's violins. The chapter will discuss some particularly interesting violins, or aspects of Joachim's association with particular instruments.