A little sunniness, a couple of smiles, finally enlivened the fourth and fifth parts of the otherwise sober program Pierre Boulez and his touring Ensemble InterContemporain brought to Westwood Tuesday night. And not a moment too soon.
These visitors from Paris, the celebrated French composer-conductor and his 31 instrumental associates, had not appeared here together since the group made its U.S. debut 7 1/2 years ago on a basketball court at UCLA. This time, they occupied a more commodious university facility, the 1,456-seat Wadsworth Theater, off-campus. A large and serious audience greeted their appearance.
The uplifting portions of the program, after intermission, comprised Boulez's own "Derive 1" (1984) and "Derive 2" (1988), shortish, pungent and engaging pieces tight in construct and lean in rhetoric, and the sometimes jazzy, usually lighthearted Piano Concerto (1987) by Gyorgy Ligeti. These provided contrast to works of more limited color and character: Edgard Varese's "Integrales" (1925), Antoine Bonnet's "Les eaux etroites" (1991) and Elliott Carter's "Penthode" (1984-85).
The two "Derives," here performed by 12 players, proved complex and intriguing, delicate exercises in ornamentation and pattern-making, finally haunting. Ligeti's jaunty and provocative Concerto uses the solo piano as principal in an ensemble of 15 virtuoso instrumentalists. Young Dmitri Vassilakis was the resourceful and relaxed protagonist, achieving an apprehendable continuity in a demanding role.