Date: 2010-08-03 07:50
The "banana key" seems to persist only by strength of tradition.
It was a bad idea on a plateau instrument, and even an even worse idea on a ring system oboe. Ergonomically it is a nightmare as to use it your hands will necessarily be pulled out of position.
I find the that the left C# key is a huge help. Play D, press the left C# key, and voila!- you have C#. And of course you can trill from C-C# with consummate ease. Tom Hinker uses the left C# key for fast chromatic passages as well.
Once you play an instrument with a left C#,
you likely would never wish to put up with an oboe without this key.
Most of the oboists who purchase a Hiniker oboe request the left C#key.
Loree, Howarth, Rigoutat, Marigaux have the left C# as an option.
Retrofitting a left C#key to an existing oboe without it is major and expensive surgery, and very few repairmen have the skill or inclination to take on this task.
With very best wishes,