As a child I learned to play the flute on a flute with closed holes. This is quite common in the Netherlands. When I was ready for an upgrate, I bought a flute with open hole keyes. I like to play with open holes. It feels like the notes are more open and clear, especially around the F. And playing an open-hole flute gives you more options. Sometimes when people buy an open hole flute, they start closing the keys with caps. A good way to learn to play with open holes, but keep in mind that the scales of both types of flutes are slightly different. Closing the keys of an open-hole flute thus affects the sound and scale. I heard flutes change dramatically when closing the keys with caps. So a little advice: don’t close your keys if you have an open-hole flute, unless it is temporary and absolutely necessary.
Type of flute and extended techniques
Okay, back to the topic I want to write about. Is an open-hole flute necessary to play extended techniques? The answer is simple: no. But there are more possibilities with an open hole flute. Since we can choose to close half of the key, more possibilities will appear. Four techniques in particular benefit from this.
First of all, multiphonics. A particular type of multphonics can be played with alternated fingerings. More combinations are possible on a flute with open holes. That is why an open hole flute offers more possibilities. Some multiphonics cannot be played on a closed-hole flute. For the same reason, quarter tones and microtones also benefit from an open hole flute. For example, playing a G quarter sharp is easy on an open-hole flute: just open half of the key on the ring finger (left hand). Open hole flutes have more options for playing bamboo notes. And last but not least, playing glissando between certain notes is possible on an open-hole flute. For example, a glissando from G to B is quite easy.
Pieces
Composers should be aware of the possibility of a flutist playing a flute with open or closed holes. Sometimes a composer writes “Written for flute with open holes” and sometimes a composer writes two versions: one for flute with open hole and one for flute with closed hole.
Notation
Most composers add the fingering to the score if it is not traditional. If a note is to be played with the key half closed, it is notated as follows:
All discussions and opinions aside, one of the main reasons for me to play an open-hole flute is simply because it gives me more options and thus more freedom while playing.