The Songza app lets music lovers build playlists for almost any mood or situation, from "Unwinding After a Long Day" to "Cooking" or "Eating Dinner." iStockphoto.com hide caption

itoggle caption iStockphoto.com

A cyclist uses a fader to manipulate music, on Cogoo's Turntable Rider kit that blends DJ and BMX culture. NPR hide caption

itoggle caption NPR

Jay-Z and Beyonce in 2003 and 2011, aging well. (L) Frank Micelotta, (R) Julio Cortez/(L0 Getty Images, (R) AP hide caption

itoggle caption (L) Frank Micelotta, (R) Julio Cortez/(L0 Getty Images, (R) AP