A new production of Monteverdi's L’Orfeo currently showing at HAU 1 in Berlin is performed on historic instruments by baroque specialist Olof Boman and the Solistenensemble Kaleidoskop. That doesn't mean it's conventional though.
Most parts will be played by trained opera singers. But the title role is taken by Berlin-based singer and performance artist Peaches (whose act Lady Gaga washed, rinsed and ironed before recycling it), and parts of the work have been adapted specially for her. Instruments are amplified and distorted, Peaches raps, and Orfeo's exceptional vocal abilities are displayed using a vocoder.
Here's an interview with Olof Boman and some rehearsal excerpts - count me sold. Why do we never get anything like this in London?