What is "mefistofele"

Mefistofele is an opera in a prologue, four acts and an epilogue, the only completed opera with music by the Italian composer- librettist Arrigo Boito (there are several completed operas for which he was librettist only). The opera was given its premiere on 5 March 1868 at La Scala, Milan under the baton of the composer, despite his lack of experience and skill as a conductor.

However, it was not a success and was immediately withdrawn after only two performances. Revisions in 1875 resulted in success in Bologna and, with further adjustments in 1876 for Venice, the opera was performed elsewhere.