The first Earth song that Aliens will hear will be 'Across the Universe' by The Beatles

On February 4, 2008 NASA beamed “Across the Universe” into deep space. It was the 50th anniversary of NASA’s founding and the 40th anniversary of the day The Beatles recorded the song. It also commemorated the launch of Explorer 1, the first U.S. satellite fifty years ago.

It also celebrated the 45th anniversary of the Deep Space Network being launched. The Deep Space Network is an international network of antennas that support the missions to explore the universe. The Beatles were thrilled to hear about NASA’s decision to beam the song into space.

Hopefully if they hear the song, they'll send aliens that look more like ET than Xenomorphs. We can only hope.

(Source)