What's the name of this character: "&"?

Questions

In what key is the Moonlight Sonata ?

His "Slavonic Dances" were originally written for four hands on the piano, but are today better known in their orchestral version. ?

The Rakoczy March is named for the leader of what country'scampaign against Austria ?

Who wrote "Flight of the Bumblebee" ?

In 1829 Mendelssohn conducted "St. Matthew's Passion" in the Berlin opera house. This event marked the revival of what famous composer's neglected works ?