Because the month in which it takes place is october, called "Oktober" in German.
An Oktoberfest horn is a tuba.
If the person is a friend you say: " Wir hoffen dich auf unserem Oktoberfest zu sehen". In a formal context: "Wir hoffen Sie auf unserem Oktoberfest zu sehen". Plural version informal: "Wir hoffen euch auf unserem Oktoberfest zu sehen". Plural formal version: "Wir hoffen Sie auf unserem Oktoberfest zu sehen".
Oktoberfest!
Oktoberfest is as always in October! Prosit!
The largest Oktoberfest takes place in Munich. Oktoberfest is not celebrated outside of the region of Bavaria.
Oktoberfest commemorates the marriage of the first king to a princess.
Germany has the really famous Oktoberfest. There are many local events called Oktoberfest in the United States, and probably in other countries as well.
The original Oktoberfest was held in Munich on October 17, 1810, to honor the marriage of Crown Prince Ludwig (who would become KingLudwig I) and Princess Therese of Saxe-Hildburghausen (after whom the Theresienwiese festival grounds, where Oktoberfest is held, is named.)
Wir hatten viel Spaß auf dem Oktoberfest = We had great fun at the Oktoberfest.
There is no name for attendants of Oktoberfest. You might call them Volk or Teilnehmer.
You can say "Bis bald beim Oktoberfest!" in German.
The Oktoberfest in Munich receives approximately 6.5 million annually.