By the standards of the CSC Repertory, the elusive ''Ghost Sonata'' is a quickie. This is the company that offered all three ''Oedipus'' plays in a single day and the complete ''Peer Gynt'' in its five-hour glory. By contrast, Strindberg's chamber play lasts less than 90 minutes. But it's a jam-packed hour and a half, brimming with dense narrative, complex characters, and concentrated emotions.
Shifting gears impressively from the long Ibsen and Shakespeare plays presented earlier this season, the CSC company does itself proud in ''Ghost Sonata,'' which seems like a ghostly echo of the equally familiar ''Cherry Orchard'' that is running in repertory with it.
This is a finely poetic production, evoking the play's tortured family relations and deep-rooted sadnesses with a delicate balance of realism, surrealism, and sheer hallucination. The result is expressionistic in the best sense: dreamlike, yet rooted in actuality, and solidly under control every moment.
While artistic director Christopher Martin sees the work (like most CSC plays) as a parable for our time -- commenting on the fakery and flimsiness of today's society -- he has avoided tricking it up, letting Strindberg's message demonstrate its own timely and timeless qualities.
The cast includes such CSC stalwarts as Noble Shropshire, Tom Spackman, Tom Spiller, and David Aston-Reese in two roles, including the Amazonian cook. Martin directed the production in tandem with Karen Sunde, who is usually busy on the boards instead of behind the scenes; and Martin designed the set, which is fuller than usual for CSC, but never cluttered or intrusive. The music, appropriately, is borrowed from Beethoven. Thus ends another ambitious season for CSC -- the initials stand for Classic Stage Company -- in its longtime project of exploring the continuing relevance of proven masterpieces.