If a dancer is never given the opportunity to show the principal roles publicly until the role is "star" quality, the dancer cannot develop themselves as true artists. Dancers need to perform roles publicly to develop themselves.
A case in point----Many of us in NYC watched David Hallberg as a corps member---and the 'star quality' was something he did not need to develop---it was always there. Too often, technical prowess pushes dancers along much too soon.
Speaking generally, I think that is the distinction: the corps dancer or soloist in a Principal role need not dance the role at the same level as a mature, principal dancer, but for the audience not to
, there should be something special in the performance, and that can be star quality or unusual technical facility, although in my opinion, the latter has more impact in roles that don't rely on classical style.
For example, Peter Boal said about Pacific Northwest Ballet soloist Laura Gilbreath in "Dance Magazine
", "He pointed to Gilbreath’s 2009 lead performance in Balanchine’s Diamonds
. 'She didn’t do that as a rising corps member. She didn’t do it as a talented soloist. She did it as an accomplished ballerina. Laura is one of those dancers where early on you could see the ballerina.'" People went away exhilarated by Darci Kistler's early performances -- her talent was evident from what appears to be a hand-held camera video of her Odette at aged 15 (shown in the "Six Ballerinas" documentary) -- and Russian audiences went crazy over 22-year-old Allegra Kent in 1960. I knew I had seen "It" after Carrie Imler's PNB School graduation performance in 1995, because the ballerina was there.
I'm not as forgiving or interested when I don't see what the Artistic Director sees, and it looks like an exercise. My bias is that I don't care about perfect performances, but I want to see that the dancer has something to say and has gone out of his or herself to give it a shot, even if it is a stretch. (When Boal casts Gilbreath, she shows me the logic of his choice.)
I also think there is a different standard at home and on tours. Unless there are a lot of injuries/illnesses that require substitutions, tour casting is telling a new audience, one with different standards and expectations, that this is the best the company has in a role; this role reflecting the alchemy of Petipa and Ivanov and Imperial training with Balanchine's genius.