Telemann’s operas have fallen largely out of favor: I cannot recall one being given a major production in my lifetime in NYC. That is unfortunate, as he and Handel were responsible for essentially creating the Germanic opera tradition. Here is a selection from his best-known opera, Der geduldige Socrates. Rodisette’s Aria, which is occasionally selected by one of the student competitors in the Met’s annual National Council competition. In it, I hear quite a lot of Monteverdi with just a hint of what is to come with Mozart. It’s a brilliant song.
Georg Philipp Telemann, Der geduldige Socrates, “Rodisette’s Aria”:
Telemann also wrote singspiel (a form of light opera with lots of spoken dialogue, the best known of which is Mozart’s Magic Flute). This one is based on Cervantes’ Don Quixote. Here is an instrumental passage that accompanies the Don’s attack on the windmills: It’s my favorite part of the book and a great example of how Telemann borrowed liberally from Vivaldi and the Italian traditions. A minor Conversation for sure.
Georg Philipp Telemann, Don Quixote, Suite for The Attack on the Windmills:
Away from the operatic stage, the prolific Telemann also composed many lieder (secular songs)—Telemann was one of the first serious composers to take on this popular form, one that Schubert successive German composers through Richard Strauss would take to new heights. In these Telemann lieder, you can hear a wide variety of influences, from both the French and Italian schools. At times, they seem to anticipate Rossini. This recording, by the great German baritone and lieder specialist, Dietrich Fischer-Dieskau, is worth listening to in its entirety.
Georg Philipp Telemann, 7 Lieder:
A Gertus History of Music 