LENOX -- After violinist Hilary Hahn's spectacular encore at Tanglewood Saturday night, a retired Boston Symphony Orchestra violinist murmured at intermission, ``There's only one explanation -- she's bewitched."
Following her scheduled performance of the Dvorak Concerto, Hahn announced her encore, ``by Heinrich Wilhelm Ernst." Actually it was one of Schubert's most famous songs, ``Erlkoenig," in a transcription for solo violin by Ernst, an Austrian violinist who was 14 when Schubert died.
Schubert's setting of Goethe's poem recounts the legend of a terrified child approached by the supernatural Erlkoenig, who wants to abduct him. His father tries to reassure him, but the Erlkoenig is victorious, and in the chilling last line of the poem the child lies dead in his father's arms.
The singer must differentiate and characterize four voices -- narrator, father, child, and Erlkoenig -- while the pianist storms through the repeated octaves of one of the most demanding accompaniments in the song literature. Ernst poured most of this onto the solo violin with great ingenuity, although the need to play both the vocal lines and the accompaniment sometimes makes it impossible for a violinist to phrase the (unheard) text the way a singer would. The piece requires stupendous virtuosity and imagination, and Hahn supplied them; the sound she produced for the Erlkoenig's blandishingly sinister voice was uncanny.
The Dvorak Concerto was also superbly played, although other, more experienced violinists have delivered this work with more variety and character; the piece is not as smooth and bland as Hahn made it sound. The orchestral accompaniment, led by the authoritative and vastly experienced Herbert Blomstedt, suggested some of the qualities Hahn was missing.
Reading her program bio, one wondered if the young violinist -- she turns 26 this year -- were being exploited. A season containing engagements in 20 countries on three continents and in 15 states in this country may not be the best way to nurture artistic growth. The thought occurred while listening to her play the Dvorak, too; the talent is tremendous and so is the natural musicianship, but qualities like these should be protected like an endangered species.
Blomstedt, who turns 80 next year but still looks boyish and conducts with youthful energy, was born in Springfield and grew up in Sweden. Apart from a period as a Tanglewood Music Center Fellow and a decade as music director of the San Francisco Symphony (1984-94), he has based most of his career in Europe. After intermission, he presided over a remarkable performance of Beethoven's ``Eroica" Symphony.
This work has become one of the bread-and-butter pieces of the symphonic repertoire, but there aren't that many conductors who are able to banish tradition and routine and make it sound revolutionary again, and Blomstedt is one of them. His reading was clear, lithe, muscular without being muscle-bound, and rhythmically alert. One of the significant things about it was how different it was from James Levine's equally distinguished performance last season in Boston, which tells you something about the boundless possibilities that still lie within even the most familiar masterpieces.