Lang Lang (...) entered in a cloud of dry ice (...)

haha ... Lang Lang.
Thanks for your very interesting response! Part of what you mentioned touched upon another thought that I had in that, I do wonder if there's just a level of solidarity generally missing from what duos have achieved, as a duo. Something that I have been thinking about regarding ensemble (singing, in this case, especially, since I currently have a choir) is the idea of a kind of oneness where, ideally, something is reached that simply can't be achieved -and is greater than- when performing alone - otherwise why not just have a soloist? Let's say you have a bunch of fantastic individual musicians, put them together to create something greater than what they could achieve alone. Do people even see ensembles like that, beyond just something like "I want the sound of more than one or ____"?
In that sense, should a duo truly achieve a kind of solidarity that acts and musically behaves as its own identity, and not two separate identities coming together, but ONE sound, one voice, one idea, then I would think it would be possible for audiences to accept a duo as
one. But, I also can see in my mind's eye and imagination that you could choreograph and stage things in particular ways to really aid in communicating that concept.
Also, it seems it's one thing for both to be independently astounding musicians, but it's even still another to have a similar musical makeup and to share in having a musical message. In that sense, I would think that you can't actually just invent a superior duo, but that there has to be something intrinsic about each individual and those individuals fitting in such a way that creates an outstanding blend, and that blend being the single voice that is "greater" than the one. I am also curious if ego inevitably gets into the way, or an inability to be fully musically disclosing to another individual?
It seems to me that if duos were moving audiences and fully communicating musical ideas, they would have a different place in the culture ... but, maybe that's wrong! Not everybody, nor everything that is
great, is necessarily recognized as such by popular opinion!