Most professional violinists, even if they are famous and well-paid, can’t afford a Guarneri or Stradivarius. These instruments cost millions, $3 to $5 million being an often quoted figure. Provenance and condition of course play a large part in the value. So how do many artists obtain a violin they covet? Robert McDuffie set up a limited partnership where his daughter’s friends’ parents, childhood friend and R.E.M. bassist, Mike Mills, and N.F.L. commissioner, Paul Tagliabue, purchased shares of a 1735 Guarneri del Gesu. Many violinists obtain their instruments from corporate sponsorships or borrow from foundations set up to loan out instruments. Some musicians do well enough that they can eventually purchase their favorites. Robert McDuffie has his on a 25 year lease from his partnership. After that, they can reap the benefits of their investment by selling it. But I think most of them aren’t doing it for the money.