Kacey Musgraves gains momentum with a 42-38 jump on Hot Country Songs with debut single "Merry Go 'Round" (Mercury). As a songwriter, the Texas native has placed cuts on albums by acts like Martina McBride and Miranda Lambert, the latter recording Musgraves' "Mama's Broken Heart" on 2011's "Four the Record". (Kelly Clarkson also sang it on ABC's "Duets" earlier this year.) Also in 2012, Musgraves has opened for Lady Antebellum (on the trio's recent European tour) and Alison Krauss.


EDM trio Krewella dances onto the Billboard charts, as the newly minted Columbia Records act hits Dance Club Songs and Dance/Mix Show Airplay with different tracks. On the former, "Killin' It" enters at No. 46; on the latter, "Alive" launches at No. 21. The Chicago group -- comprising sister vocalists Jahan and Yasmine Yousaf and producer Kris Trindl -- has earned nearly 3 million views on its YouTube channel, while its "Play Hard" EP reached No. 19 on Dance/Electronic Albums in July.


Michigan-born, Los Angeles-based brother-and-sister duo Blondfire (Bruce and Erica Driscoll) are approaching the Alternative chart with "Where the Kids Are" (Tender Tender Rush). SiriusXM's Alt Nation channel led all panelists with 23 plays for the song in the Sept. 10-16 Nielsen BDS tracking week, followed by KRBZ Kansas City, Mo. (16) and WROX Norfolk, Va. (14). The duo first named itself Astaire but adopted Blondfire after being threatened with legal action by representatives of the estate of actor/dancer Fred Astaire.


Shane Dawson's self-released "We Are Never Ever Getting Back Together (Spoof)," featuring Wendy McColm, debuts at No. 10 on Comedy Digital Tracks. The cut ribs Swift's history of writing songs about her ex-boyfriends, warning, "You should never, ever break up with Taylor," lest one be skewered in a multiformat hit. Dawson has already earned online prominence: ShaneDawsonTV is the eighth-most-subscribed-to YouTube channel, boasting more than 2.8 million subscribers.

Reporting by Keith Caulfield, William Gruger, Wade Jessen and Gary Trust.