From Thursday's New York Times.  This is nice to read from the Chorus Director Donald Palumbo of the Metropolitan Opera:

"Perhaps the
ultimate challenge last season, for the chorus as well as Mr. Palumbo,
was Philip Glass’s “Satyagraha,” with its vast expanses of abstract repetitive choral patterns to be digested, memorized and sung in Sanskrit.“We
had never encountered anything quite like it before,” Mr. Palumbo said.
“There was a lot of resistance to Glass’s idiom at first, and the
chorus had a hard time making a connection with the language. But after
several weeks of plugging away, everything suddenly fell into place.
Within a span of just one or two rehearsals, the learning curve took
off, and we went from struggling to almost complete comprehension. When
that happened, despite all the physical demands the piece makes, it
became an intellectual joy for the chorus to sing, and all the
performances came off on a real high.”