cross-fingering

Cross-fingering is a technique used in playing certain wind instruments, particularly those with a six-hole system like the Baroque transverse flute and oboe. It involves using fingerings that are out of the standard serial order to produce specific chromatic tones.12

This method was developed to achieve notes not readily available through simple hole covering. For instance, to play an 'f' instead of an 'f#', a player might cover a hole below an open one. However, certain notes, like 'e♭/d♯', were impossible to produce without an additional hole and a special key mechanism. The evolution of key systems, notably by Theobald Boehm, further refined fingering techniques, enhancing technical dexterity and tone quality. Fingering itself refers to the method of using fingers to play an instrument or the markings indicating this method.23