Structure and Characterization in three time periods is a study and an analysis based on my performances as Ruth in Later the Same Evening by J. Musto and M. Campbell, Despina in Cosi fan tutte by W.A. Mozart and L. Da Ponte, and Atalanta in Serse by G.F. Handel with a libretto based on works by N. Minato and S. Stampiglia (librettist unknown). This dissertation focuses on the different structure of the three operas and the characterization of each of the three roles. In this project, the unique and important aspects and challenges in interpreting the three different roles – Ruth, Despina, and Atalanta - from three different time periods – the twenty-first century, Classical, and the Baroque - are explored. The recorded portion of this project consists of CD and DVD recordings of the three performances. Later the Same Evening was a world premiere opera, presented at the Kay Theater, Clarice Smith Performing Arts Center, on November 15th – 18th 2007 and at the National Gallery of Art, Washington D.C. on December 2nd, 2007. Cosi fan tutte and Serse were performed at the Kay Theater, Clarice Smith Performing Arts Center in April 23rd, 25th, 27th 2008, and April 18th, 22nd, 24th, 26th 2009, respectively.