The songs of summer 2013 are definitely a throwback to the 70's. Robin Thicke's 'Blurred Lines,' which is at number one on Billboard's Hot 100 Chart, is a radio favorite and is inspired by Marvin Gaye's 'Got to Give It Up.' Daft Punk and Pharrell's disco-themed 'Get Lucky,' and Bruno Mars' 'Treasure' are also 70's influenced tunes. Kristina Behr has the story.