Would a sufficiently-capable (but still bound by the laws of physics) nonhuman being (such as an animal, a robot, or an alien) be capable of consistently doing this thing once? This is tricky because I can imagine a hypothetical scenario where an AI does this thing. But would it even count? Let’s just say that Tony’s story would not have played out the way it did if he wasn’t human.
Would such a being be capable of doing it multiple times? See above, because this just brings us even further into “would it even count?” territory.
Does this thing depend on a conventional but arbitrary standard (such as the length of a meter, the International Date Line, or the arrangement of the calendar)? It concerns the definition of a term, if you count that.
Specifically, does it involve any convention concerning the measurement and/or recording of time? No
Doing the thing requires a talent or ability that many people don’t have? (If yes: physical ability? Intellectual ability? Artistic?) Yes, artistic ability
It requires a lot of money? No, though it probably doesn’t hurt
It requires a lot of some other resource? No
There’s some limiting factor affecting how many people can do the thing? (Like visiting the International Space Station or something?) No
There’s an element of luck / being in the right place at the right time involved? Yes
Did he win a Grammy award with each of five bands in the same year? No
Or some other award? No
Did he achieve a certain achievement with 5 different bands? Yes