<p>Actually you do not dress formally, but business like. Think interview not recital. A strapless dress is not appropriate. It does not have to be black but a nicely draping jersey dress and not too high heels is good. [Evan</a> Picone Dress, Three Quarter Sleeve Marilyn - Work Dresses Dresses - Women’s - Macy’s](<a href=“http://www1.macys.com/catalog/product/index.ognc?ID=341493&CategoryID=46369]Evan”>http://www1.macys.com/catalog/product/index.ognc?ID=341493&CategoryID=46369)<br>
And as others have said, for piano, slacks and a nice blouse are good, too.</p>