Coming to the aulos from the triplepipe, my mind is clear. In order to give all ten fingers the possibility of virtuosic movement, without the instrument slipping out of your hands, it’s best only to open one hole at a time. This is known as ‘closed fingering’ and it is the most widespread fingering system in living piping traditions around the world.
Closed fingering has the immeasurable musical advantage of creating a ‘virtual’ drone. This is made up of the gaps between each note; these remainders have a pitch which our brains process as a second voice. There is great art in giving this second voice a life of its own, raising it from being the floor sweepings of the upper voice to something which adds significant musical interest and dramatic impact. There are infinite shades of staccato, shifting the balance of power between the upper and lower voices; more staccato increases the prominence of the lower voice; less staccato shifts attention to the upper voice; and when you play legato, the lower voice (or virtual drone) disappears completely.
Legato playing is not the end of the road, however: you can warm up the upper voice still further, letting the sun out on the sound, by lifting off more fingers. This increases the volume but is only practical when the melody is stationary or slow-moving. Otherwise, the instrument would slip.
Everything I’ve written above is true of traditional Sardinian launeddas technique. The fact that the aulos has thumb holes only increases the need for stability. Closed fingering supplies this better than any other system: the more points of contact there are between the fingers and the pipes, distributing the weight of the pipes and keeping them stable, the less tension is needed at any one point. This liberates the fingers to make music.
