Andreas Scholl believes that the strength of the countertenor voice lies in its ability to transcend concepts of masculinity and femininity, to express the whole human experience.

No doubt the renowned 18th century castrato Senesino, for whom all arias in Friday's concert were written, had a subtly different view of the gender issue, but Scholl certainly brings an almost elemental beauty and purity to this operatic subject matter of earthbound love and power politics.

Yet the delicacy of the Scholl sound in a venue the size of Symphony Hall came as a shock, and it sometimes felt that the instrumentalists of Accademia Bizantina, for all their fastidious musicianship and gossamer lightness, were impinging on the singer, particularly in the exquisite anguish of Cara Sposa from Handel's Rinaldo.

But Scholl knows what he's doing. He made no attempt to fill the acoustic, producing a fuller tone (to shattering emotional effect) only sparingly at the top of phrases, and instead commanded attention through eight arias (by Handel, Albinoni, Porpora and Lotti) simply with his sweet, luminous sound, perfect intonation and stunning control of long lines.

Without volume, his Giulio Cesare (Handel) lacked heroism, although his virtuoso agility was greeted with special enthusiasm by a loyal but under-capacity audience.

This was no one-man show, however.

The interminable re-tuning of Accademia Bizantina's period instruments was a significant irritant but conductor Ottavio Dantone and his band more than redeemed themselves in the flamboyance of Geminiani's La Follia and the spine-tingling exchanges between first violin and Scholl in Discordi pensieri.

Clare Mackney