![Anatomy_Summer_Jam-01](http://s3.r29static.com/bin/entry/971/x,80/1277090/anatomy-summer-jam-01.jpg)
Genre
Stylistically speaking, R&B is your best bet: 36% of the last 25 Summer Jams fall under that umbrella (ella-ella eh-eh). Pop takes second with 25%, followed by hip-hop (16%), dance and rock (tied at 12%), and reggae-fied Elvis covers done by middle-aged British dudes (4%).
![Anatomy_Summer_Jam-03](http://s3.r29static.com/bin/entry/595/x,80/1277094/anatomy-summer-jam-03.jpg)
Gender
This is a man’s world, but just barely: 36% of our sampling features solely male vocals. The remaining 64% is split equally between female-sung tunes and co-ed numbers, like Jay Z and Beyonce’s “Crazy In Love” and Los del Rio’s “Macarena,” both classics in their own right.
![Anatomy_Summer_Jam-04](http://s1.r29static.com/bin/entry/3f5/x,80/1277091/anatomy-summer-jam-04.jpg)
Rhythm
You’ll break a serious sweat dancing to 52% of these songs, while 16% encourage head nods and muted grooving. Then, there are the ballads: 28% of Summer Jams are engineered for swaying, bawling, or both. As for Matchbox 20’s “Bent,” scientists still aren’t sure whether there’s any groove there.
![Anatomy_Summer_Jam-05](http://s3.r29static.com/bin/entry/ee8/x,80/1277095/anatomy-summer-jam-05.jpg)
Lyric and Mood
Whether you’re writing a ballad or a banger, keep it light: 28% of Summer Jams essentially say, “Baby, I love you.” Other popular sentiments: “I wanna sex you up” (24%) and “Let’s party all freakin’ night, y’all” (16%). Only two songs are about flat-out heartbreak (one by Richard Marx, the other Mariah Carey), while two others are confessionals about cheating on your boo (Usher), and kissing a girl and liking it (Katy Perry). The others include Brandy and Monica’s “Boy Is Mine” catfight and Diddy’s B.I.G. tribute, “I’ll Be Missing You.”
![Anatomy_Summer_Jam-06](http://s1.r29static.com/bin/entry/e84/x,80/1277092/anatomy-summer-jam-06.jpg)
X Factors
People love novelty songs, but not enough to make ‘em Summer Jams. Only 12% of these tunes quality as silly trifles, and that’s including Sir Mix-a-Lot’s “Baby Got Back,” which is probably smarter than anyone realizes. Amid all the sexy talk, at least two — Carly Rae Jepsen’s “Call Me Maybe” and All-4-One’s “I Swear” — are earnest love songs sung by swooning youngsters not yet experienced enough to write a “Blurred Lines” or “Promiscuous.” Innocence can sell, but it’s probably safer to go with an ode to big butts. That, or cautionary tales about AIDS and drugs. It totally worked for TLC.
![Anatomy_Summer_Jam-02](http://s2.r29static.com/bin/entry/940/x,80/1277093/anatomy-summer-jam-02.jpg)