As Sloan explains it, three elements that make a song sexy are “intimacy, tension, [and] suspense.” The tension comes from songs that hold a steady beat and don’t let you speed up to quite reach a state of euphoric release, especially in a playlist. You can hear it in “Love to Love You,” which maintains a steady synthesized beat throughout, punctuated by faster high-hats and funky bass — the song hits on every downbeat, there is always something happening, but it never deviates from a driving tempo that keeps momentum tightly reigned in. Britney Spears’ “I’m A Slave 4 U” (from 2001) does the very same thing, but on the upbeat which makes it feel faster even though the beats per minute (BPM) are only slightly faster (96 vs. 110). If you lay them side by side in a playlist you might notice your body reacting by switching up your motions. Tempo and whether a song emphasizes downbeats or upbeats have a huge influence on how sexy we think a song is — if it’s too slow or too fast, it no longer mimics the movement of the body during sex. Or, at least, not the kind of sex we want to have.