Czech harpsichordist and conductor Ondrej Macek plays from Antonio Vivaldi's lost and found opera Argippo at a news conference in Prague Monday, April 21, 2008. The opera has only been known from a period print of the libretto deposited in Prague's National Library while musicologists believed the scores had been lost for ever. Macek found a substantial part of its manuscript in the private Thurn-Taxis archive in Regensburg, Bavaria, in 2006. The opera was performed for the first time in 1730 in Prague for which Antonio Vivaldi composed it. He also probably conducted the opera then. Ondrej Macek is now preparing its new world premiere at Prague Castle on May 3.