The Pierrot Ensemble, named after Schoenberg’s Pierrot Lunaire and consisting of flute, clarinet, violin, cello, and piano, has, since its inception, been a signature assembly for contemporary music. The preferred version of the ensemble also includes a percussionist: the “Pierrot plus Percussion” grouping is the default core membership for many new music groups. Even after dozens, if not hundreds, of pieces have been written for “P+p” ensembles, there is still plenty of vitality left in the genre. This was abundantly in evidence on the Saturday afternoon concert on July 23 at Tanglewood’s Festival of Contemporary Music, where several of the