Because Ptolemy's tunings provided the necessary starting point for the interpretation of modal characteristics, much of the foregoing study of the fragments was concentrated on possible connections to the cithara. For the aulos we have no similar written source; hence we can consider this instrument only now that we have obtained an overview of the musical structures of melodic practice.

For the aulos there is once more a huge amount of pictorial evidence, which must be evaluated with the usual caution. But here we have in addition a number of excavated instruments. Most of these are however highly damaged. Usually the upper end is missing, so that possible pitches can be deduced only indirectly, by finding the instrument length with which the finger holes would yield a plausible scale. But although this principle seems promising, it has not yet produced convincing results for most of the early finds. One cause is that we have almost always but a single pipe, while especially on some of the more primitive types with not more than five finger holes per tube, the notes of the two pipes probably complemented each other in some way. An additional complication is the rich number of different instrument types and sizes, mentioned by several authors from Aristoxenus on.

EARLIER AULOI AND THEIR ICONOGRAPHY

For the earlier times, we must therefore resort to the iconography also, mainly from vase paintings, even if this is the least trustworthy kind of source as regards details of playing.