As the lutenist in San Francisco Opera’s 2011 production of Xerxes, I play not only an unusual role in the orchestra, but also a number of unusual instruments not well known to many opera goers. While the traditional opera repertory is not often thought of as utilizing improvisation, baroque music has a rich history of it. Nowhere is this truer than in this production of Xerxes where the harpsichord and I make up what could essentially be called the rhythm section of the orchestra. We play from a bass line, much like what a cellist uses, but we have figured bass (numbers under the bass notes which tell us which harmonies to play) added to our parts. Similar to how a jazz pianist might accompany a song, both the harpsichord the lute family instruments play the harmony, which is improvised in keeping with musical content of the composer.