Earlier in her career, Argerich developed a reputation for canceling concerts often, although in recent years she has regularly appeared as scheduled for her U.S. dates, particularly performances with Dutoit (to whom she was once married). During the past month, she has played concertos with Dutoit for three dates each with the Orchestre de la Suisse Romande in Geneva and the Zurich Tonhalle Orchestra and four dates (last week and this past weekend) with the Philadelphia Orchestra.

According to a statement released this morning by the Boston Symphony, Argerich is now suffering from physical exhaustion and has been ordered by her doctor to return home to Europe. Her next scheduled performances are from April 11-21 at Argerich's Meeting Point (www.argerich-mf.jp), a chamber music and education festival she founded in Beppu, Japan.

Replacing Argerich in Boston this week will be Yuja Wang, a graduate student at the Curtis Institute in Philadelphia and a 2006 recipient of the Gilmore Young Artist Award. She will perform Tchaikovsky's Piano Concerto No. 1. The rest of the program remains unchanged: Rimsky-Korsakov's Russian Easter Overture and Stravinsky's Symphony in C.

Wang's career has already received a boost from one high-profile substitution — for Radu Lupu with conductor Pinchas Zukerman and the National Arts Centre Orchestra (Ottawa) in February 2005. This season she makes her debuts with the New York Philharmonic and the Houston, Chicago, San Francisco and NHK Symphony Orchestras; she will perform with the last three under Maestro Dutoit.