Period Instrument Performances

Why would anyone want to perform the same piece that can be played perfectly well by a modern orchestra on instruments of an older design that wheeze or don't have a rich sound or even are so difficult to play that they don't sound good? The fact is that up until the end of the Nineteenth Century there were instruments used that were not as robust as the modern replacements, so why would we want to go back to them?

The answer was given to me by listing to Nicholas Honnencort conducting an ensemble of period instruments in the last movement of Bach's Forth Brandenburg Concerto about ten years ago. This is one of my most favorite pieces and I had known it for 30 years before and owned an orchestral score which I had looked at while listening many times before. Then it became obvious, all the inner texture, in the second violin and viola part, all the quarter note and eighth note accompaniment could only be heard in the original ensemble because the modern analogues drown them out. The modern string bow, the modern flute, the bigger resources of a modern orchestra overwhelm Bach's original idea. He wrote for the old instruments with their translucent tone. What we hear in modern instruments is a fuller sound, but it is like redoing a painting originally done in watercolors in oils.