The probability is that both single and double reeds were at times used with the Greek aulos and the Roman tibia.
How then about makers of the flute (aulos) and players on the flute?
On a mosaic of Monnus in Trves10 is represented an aulos which also appears to have a beak-shaped mouthpiece.
The bore of the aulos was very much narrower than that of the clarinet.
This is more fully explained in the articles Clarinet and aulos.
A similar or still more rapid development took place in the flute (aulos).