Over the years, I have repeatedly been confronted with this question: when talking about our ancient double pipes, should we not use the plural (Greek: auloi; Latin: tibiae), instead of the singular (aulos/tibia) – isn’t it two pipes, after all?
My general answer would be, if we use ancient terms, we ought to stick as closely to ancient usage as possible. Anything else is horribly confusing for non-specialists, who inevitably become entangled between ancient and modern acceptations, mistaking the latter for the former and consequently reading wrong meanings into the sources. Ancient usage, please, or non-ancient words!
So that should be easy enough, right? Well, a close look at the texts shows that it’s a bit more complex… but still… As far as I see (I give only Latin examples, but Greek usage is close enough),
- the plural auloi and tibiae may denote several instruments as well as a pair of pipes. The latter, I think, is more colloquial (eripe ex ore tibias “pull the pipes out of your mouth”: Plautus, Stichus 718).
- singular aulos and tibia generally refers to a pair of pipes (biforem dat tibia cantum “the tibia sends forth its double-bore music”: Vergil, Aeneis 9.618),
- unless one explicitly distinguishes the members of the pair (dextra tibia alia quam sinistra “the right pipe is different from the left”: Varro, Res Rusticae 1.2.15).
Therefore, I think, in order to denote a pair of pipes, using the singular makes the most sense, because this clarifies it is a pair of pipes. If we say “auloi” or “tibiae”, one would more naturally understand we are talking about more than one instrument. On the other hand, whenever I talk about a single extant pipe I prefer saying “pipe”, not aulos or tibia – also to emphasise that this is not a complete instrument: “Pompeii Pipe 3”, but “the Louvre aulos”.