When you have a choice of three fingerings for the same note you can select for different reasons. Very often for example going down from a D to a C it is very difficult to make it smooth so I would say choose one of the other fingerings. But also I think they have different tone quality. So for example the usual F is a lot brighter than the fork F. So if I had a piece where I wanted to make a slightly muted sound, a little bit more foggy and not so focused, I might actually just use the fork F anyway. There might not be a difference but let’s see (plays). That is quite a brash, harsh sounding F. If I then wanted to be a bit more gentle (plays) I’m not sure if you can hear that actually?Right down at the bottom of the instrument if I need to close all the holes right down to the bottom I can’t reach all the way down there without moving vast amounts. So there is a Bb key down here and that closes all the keys here. That has a great fog horn sound. I love this sound down at the bottom (plays). Very fog horn. That is the bottom note of the oboe. There is not much you can do that is sort of there. I mean you can play a little bit quieter (plays quietly) but it is quite hard to change the tuning. On the rest of the oboe you can change the note with your mouth.
In the Pulcinella Suite by Stravinsky there is a great oboe tune, where the oboe is playing a nice little tune and then ‘blrru’ it comes out with a bottom fog horn C which is quite surprising. Um and rather beautiful (plays).
What is hard on the oboe is when you play at a high pitch to then change your embouchure and go down to a low pitch. So (plays octaves) you are having to alter quite a lot and again it is helped a lot by the reed. Some reeds are very good at low notes and others are better at higher notes.
It is usually thought the oboe can go from a Bb to top G, 3 Gs above middle C. It is possible to squeak out notes even higher (plays high). Going bright red in the face and need good reeds. And if you bite, put your teeth on and use a completely different embouchure and bite, with the teeth on the back of the reed (plays) you can sometimes get even higher.