During its 43 years of existence, the Tokyo String Quartet sometimes has been criticized for being too polished. But rather than indulge in they-hate-me-because-I’m-beautiful sulking, the quartet simply continued to play magnificent concerts and release excellent albums. Recent recordings include the Beethoven quartets, played on the ensemble’s set of Stradivarius instruments all owned by the famed 19th-century violinist Niccolo Paganini. Now the group is on its final tour before disbanding at the end of June. Widely regarded as one of the best string quartets in the world, it will perform in Richmond on Saturday before giving final concerts in Philadelphia and New York, then touring Japan and Australia. While in Richmond the musicians also will give master classes. Teenage violin, viola, and cello players will compete to win spots being personally coached by the elite performers. The classes are open to anyone. The master classes meet Saturday, May 4, from 2 to 4 p.m. Later, the Tokyo String Quartet performs works by Beethoven, Bartok and Mendelssohn at 8 p.m., with both events at Virginia Commonwealth University’s Singleton Center for the Performing Arts. Tickets are $30-$34. vcu.edu/arts/music/dept/index.html.