XXIXb:2, is an opera in one act by Austrian composer Joseph Haydn to a German libretto, possibly by Prince Esterházy's librarian, Phillip Georg Bader.

[9] Premiering in 1773 for a visit from Empress Maria Theresa,[2][10] Philemon und Baucis is Haydn's first puppet-opera,[4][11] and the first known to be written for the Eszterháza Marionettentheater (puppet theater).

[8][18][19] The rest of the puppet-opera, including the arrival of Jupiter, the pageant, and the epilogue, which glorified the Empress and the Habsburgs,[12][20] remain lost, likely destroyed in the Eszterháza fire of 1779.

Touched by the couple's hospitality and grief, Jupiter and Mercury reveal their true identities and reanimate the bodies of Aret and Narcissa from the ashes.

Filled with gratitude, Philemon and Baucis plead with Jupiter to turn their hut into a temple so that they may serve his honor as priest and priestess.