How to double tongue on french horn

1. How do you tongue fast on a French horn?

How do you tongue fast on a French horn?

focus the lip “buzz” accurately on the desired pitch, 2.) move only the tip of the tongue, and only in an up-and-down direction, 3.) make the stroke of the tongue as short as possible, and, 4.) do not create a tight hermetic seal, but let the tongue touch lightly—almost to the point of letting air escape between notes.