The Eliot String Quartet, from left: Michael Halbrook (viola), Jordan Bartow (cello), David Pazderski (violin), and Austen Speare (violin) practice Mozart’s String Quartet in F Major, K. 590 while Rhonda Rhider (center with cello) coaches their performance at a public masterclass June 18, part of the Harvard Cultural Collaborative’s week-long music festival. (Photo by Lisa Aciukewicz)