My guess is that, when the San Francisco Conservatory Opera Theatre began preparing their performance of L'Egisto, there was not a whole lot of familiarity with the music of composer Francesco Cavalli; so both composer and opera were probably even greater unknowns to most of the audience. At least I had the advantage of seeing L'Ormindo, the opera that Cavalli composed almost immediately after L'Egisto back in the days when I would take the train from Stamford to New York for as wide a variety of musical offerings as my schedule could manage. However, in the interest of full disclosure, I have to confess that about all that my wife-to-be and I can remember from that event were the really eye-dazzling costumes by Beni Montresor. Beyond that I think the performance was in the Auditorium of Hunter College but would not bet anything serious on that. According to the Wikipedia entry for L'Ormindo, it was performed by the Pittsburgh Opera in February of 2007; but I doubt that this had anything to do with the Conservatory's decision to prepare L'Egisto as this year's full opera project. A more likely explanation is that director Richard Harrell had recently staged Cavalli's La Calisto for the San Francisco Opera Center and wanted to give this composer another try.
I certainly cannot blame Harrell for his interest. Cavalli's obscurity today is one of those cruel artifacts of history. As Nathaniel Marken's program notes observed, L'Egisto was one of the greatest hits of the opera repertoire in the latter half of the seventeenth century, at least "up and down the Italian peninsula." There could be a variety of reasons for this. For one thing it may have one of the largest casts of solo voices in the opera repertoire (at least if you do not count Der Ring des Nibelungen as a single opera); so, whatever one may have thought about the plot, one could always attend a performance as a "monster" recital (in the same sense of the "monster" piano concerts arranged by Louis Moreau Gottschalk two centuries later). However, the plot itself is rather a departure from the prevailing esthetic in that it is not tragedy, comedy, or history; rather, as we learn from the Wikipedia entry, it was called a favola dramatica musicale, favola being Italian for "fairytale" or, if you want a similar-sounding English word, "fable." Whether or not this was a deliberate effort to situate the work beyond the pale of Aristotelian esthetics, there is something decidedly different about the plot; and, if Aristotle is being rejected, then this may be because his belief in the theatre as a source of education is also being rejected. L'Egisto is there to entertain and nothing particularly more.
That emphasis on entertainment may explain the large cast. In the interest of variety, we have mortals (such as Egisto himself), gods (such as Venus and Apollo), demigods (such as Cupid), allegorical figures (such as the Four Hours), and even four heroines from a rather diverse collection of other fables (Semele, Phaedra, Dido, and Hero). Furthermore, all characters are decidedly human in their strengths and weaknesses (which, in the case of the elderly nurse Dema, includes sexual appetite), which means that the Aristotelian classification of characters as noble or base is also being rejected. Perhaps the work was so popular because, while the composer and librettist (Giovanni Faustini) may have been Italian, the "culture" of the plot is more in keeping with the humanist outlook of Northern Europe.
This sounds like quite a lot to cram into a single opera. So anyone familiar with the background of this opera was probably braced for a very long evening. However, the other thing I remember about the performance of L'Ormindo that I saw was that it was very skillfully edited down to a form that honored both plot and music without demanding the endurance required for sitting through Das Rheingold. I assume that both Harrell and conductor Christopher Larkin had a hand in editing L'Egisto down to a length sympathetic to the audience sitting in the Cowell Theater, in which case they both came up with a good strategy for moving the plot along at a brisk pace without depriving any of the singers of their respective opportunities for virtuoso display (which may include the first real mad scene in the history of opera as we know it). So, if this was an opera that was intended primarily (if not entirely) to entertain, then the "teamwork across time" of the "creative staff" of Cavalli and Faustini and the "production staff" of Harrell and Larkin came off totally successfully.
While most Conservatory performances take place only once, four performances were scheduled for L'Egisto (with two casts), All of my impressions came from Opening Night, meaning that three performances remain: tonight, tomorrow night, and Sunday afternoon. I suppose that the strongest of those impressions is that Cavalli really does not deserve the obscurity his ghost must currently endure. There is nothing wrong with entertainment for its own sake when properly executed, and this particular execution has shown itself to be a real gem. Besides, how likely is it that this kind of lightning will strike again in the near future?