There is more than one artist with this name: 1) Marietta was an artist from the 1980s whose most popular song was Destination Unknown from the Top Gun Soundtrack. --
2) Marietta is an indie emo band from Philadelphia. They formed in late 2011 and began playing shows in 2012. They draw inspiration from other midwest emo-revival bands as well as from '90s emo bands such as Mock Orange, the deftones, and Braid.

Read more about Marietta on Last.fm.