Only one song each year can be named the “song of the summer.” In 2008, it was Katy Perry’s “I Kissed a Girl.” The next year, it was the Black Eyed Peas “Boom Boom Pow.” Last year, Perry topped the list again with “California Gurls.” With summer almost halfway over, no song has asserted itself as the song of summer 2011. There are, however, a few contenders. Here is a list of five songs competing for the elusive top spot:

1. “Rolling in the Deep” by Adele

“Rolling in the Deep” is Adele’s lead-off single for her second album, “21.” Since its Nov. 10, 2010 release, “Rolling in the Deep” has topped the Billboard Hot 100 list five times. With her soulful voice and powerful lyrics, Adele appeals to a huge range of music listeners, which is one reason why “Rolling in the Deep” is doing so well on the charts. 

“Rolling in the Deep” certainly isn’t like previous summer songs like “Boom Boom Pow” or “I Kissed a Girl,” but maybe that’s why people like it so much. Adele causes her listeners to think and evaluate all aspects of life. Maybe summer 2011 is the summer of introspection, and “Rolling in the Deep” is the perfect song to aid the self-examination process. 

2. “The Edge of Glory” by Lady Gaga

Lady Gaga, above all else, is a talented musician. Behind her odd fashion choices and bizarre hairstyles, Lady Gaga has a voice that is both unique and beautiful. Beginning with “Lovegame” and “Poker Face,” Lady Gaga has continually produced hit after hit for the past two years. Her newest singles, however, have not been as popular as her past ones.

“Judas” and “Born this Way” have powerful messages. This is a distinctive change from Gaga’s past singles. Americans may not be ready for this new Lady Gaga. That is why “The Edge of Glory” will offer Gaga her best chance at grasping the title of the “song of the summer.” “The Edge of Glory” is much more upbeat than Gaga’s other singles from her newest album “Born this Way.” “The Edge of Glory” still has a powerful message, but the message is subtle, and is overshadowed by the fast beat. This may mean that the song will perform better than “Born this Way” or “Judas.”

3. “E.T.” by Katy Perry

With two previous “summer songs” under her belt, Katy Perry has proven that she knows how to top the charts in the summer. Perry is all about producing catchy, light-hearted songs. Unlike Adele and Lady Gaga, Perry’s intentions when writing a song is not to inspire or shock but to merely make a song that people sing and dance to. 

“E.T.,” however, is a little different than “I Kissed a Girl” and “California Gurls.” To begin, the tempo is slower than the first two. Perry’s voice is also a bit deeper in “E.T.” compared to her other songs. Furthermore, there is a techno beat in the background during the chorus. All of these aspects could mean that “E.T.” will perform worse than Perry’s other singles. Or, they could mean that the single will be her biggest hit. Time will only tell. 

4. “The Lazy Song” by Bruno Mars

For many people, the summer is a time to relax and take it easy. Bruno Mars’ “The Lazy Song” is perfect for those people. The song is great to listen to while laying on a hammock or basking in the sun. Mars’ smooth voice is capable of making you forget all of your worries. 

Bruno Mars is no newcomer when it comes to releasing top-charting singles. His first two singles, “Grenade” and “Just the Way You Are” both reached number one on the Billboard Hot 100 list. While his first two singles were love ballads, “The Lazy Song” is more of a bob-your-head, feel-good song. Mars’ voice in “The Lazy Song” is as good as it has ever been, and the music video to the song is hilarious.

5. “Till the World Ends” by Britney Spears

With all this end of the world talk, Britney Spears’ “Till the World Ends” may be the best song to define summer 2011. Harold Camping, however, is not the only reason why Spears’ song may nab the “song of the summer” spot. Point blank, Britney Spears knows how to produce hit songs. Even when her personal life is in shambles, this girl can still make a good song. 

“Till the World Ends” is reminiscent of “Womanizer,” “Gimme More” and even “Toxic.” With their catchy choruses and fast tempos, these songs are meant to get the listeners dancing. If you believe that the world will end on Oct. 21, why not dance the rest of your life away? Depending upon how many followers Harold Camping has, “Till the World Ends” may be this year’s song of the summer.