If any one radio station in the country seems to be setting the trends right now, its the Bay Area's KMEL, which—even better than its Atlanta competition, or its Cali bretheren in L.A.—has one of the best playlists in the country. With a unified blend of L.A. and Bay Area beats over that uptempo style pioneered by the HBK Gang and DJ Mustard, Cali has been throwing numbers on the board. DJ Mustard alone has four songs in the hip-hop airplay top ten. 

I've repped pretty heavily for "2 AM" already—another Left Coast jam liable to make it big in the next few months. Same goes for Cassie soundalike Tinashe, whose delicate approach on "2 On" is balanced by Mustard's muscle. It's tough to imagine Rayven Justice's "Slide Thru" won't join them, even though the Migos remix is already a month old and the original video's been out for three. Produced by Young California, DJ Carisma, and DJ Amen, it shows how very slight variations on an existing formula can create radically different effects on the listener, the cartoonish "I'm Different" pianos mutating into enigmatic atmosphere.

Another song in this vein liable to have a big few months is Derek King's "Jump," with Kirko Bangz and Sage the Gemini. Since the success of Sage's "Red Nose" and "Gas Pedal" cuts last year, he's popped up on remixes across the map—a good sign that a song is gathering momentum is that it emerges with a Sage guest spot. (See also: the Hit-Boy produced "Kiss It.")