Musicians: Which note does piano gives to flute to help it tune before a perform

Question:

Musicians: Which note does piano gives to flute to help it tune before a performance?

When piano accompany violin, pianist gives an A for violin to tune. Does pianist need to do that for flute too? If so, which note? Bflat?

Best Answer - Chosen by Asker: I tune my flute to A440, but that's from my electronic tuner, not my piano (which is a tiny bit flat right now).

Really, if it was only the piano and the flute, conceivablly you could use any note.

I have my 2nd flute lesson tomorrow morning.... I'll ask my flute teacher (who has a M.Mus in flute) and post an edit to this message :D