The third-quarter Publisher Airplay chart produced the most dramatic changes in the rankings since Billboard began its quarterly tracking of chart share for the top 100 songs in 2006.

For the quarter, Sony/ATV Music Publishing was by far the top-ranked publisher with a 25.7% share, eight percentage points ahead of the closest competitor. But it's an accomplishment that will have to be marked with an asterisk: Sony/ATV has vaulted to the top because it now serves as the administrator for EMI Music Publishing.

On June 29, a Sony Corp. of America consortium acquired EMI Music Publishing and assigned Sony/ATV as its administrator. That means Sony/ATV had control over those EMI copyrights for the entire third quarter, which is why Billboard combined the EMI and Sony/ATV chart shares into one ranking. In landing in the top spot, Sony/ATV claimed 53 songs in the top 100, including the No. 2 track, Ellie Goulding's "Lights"; the No. 4 track, Rihanna's "Where Have You Been"; and P!nk's "Blow Me (One Last Kiss)" at No. 7.

But if the market share of those two catalogs hadn't been combined, Kobalt Music Group would have pulled off the coup of the year, surpassing all major publishers to become the No. 1-ranked company. For the quarter, Kobalt turned in a 17.5% share, which would have beat the 14.5% tallied by EMI's portfolio by nearly three percentage points.

As it is, the music publishing administration company has transformed itself from an upstart into a top competitor. In the third quarter, Kobalt handled 29 songs that placed in the top 100 radio songs, including the top three: Katy Perry's "Wide Awake," Goulding's "Lights" and Maroon 5's "Payphone" (featuring Wiz Khalifa), respectively. During the last four quarters, Kobalt has averaged the second-highest share among publishers of the top 100 U.S. radio airplay songs. This quarter, Kobalt was up, growing its share 0.8% from 16.7%. Year over year, Kobalt is up 2%.

Radio airplay was calculated based on the overall top 100 detecting songs from 1,534 U.S. stations monitored electronically by Nielsen BDS for the period of July 1-Sept. 30. The Harry Fox Agency researches the publishers' split for each track to calculate their share of those songs.

Warner/Chappell Music ranked third with 13.1%, down considerably from the 17.1% that topped our list in the prior quarter, but still up year over year from the 10.8% it captured in third-quarter 2011. While its share dropped four percentage points, Warner/Chappell still managed to place 37 songs in the top 100 radio songs, only three fewer than in the prior quarter.

Meanwhile, Universal Music Publishing Group ranked fourth with a 12.6% share. That's an improvement from the 11.3% it garnered in the prior quarter, but down from the 14.1% it had in the corresponding period a year earlier. UMPG placed 35 tracks in the top 100 songs, one more than it had in the second quarter. This time out, UMPG's top songs were "Payphone," "Where Have You Been" and Calvin Harris' "Let's Go" (featuring Ne-Yo), which ranked at No. 12.

BMG Chrysalis came in fifth, with a 5.5% share, even though it dropped some chart share from the 7% it posted in the prior quarter. The company placed 18 songs in the top 100, including the Goulding and Maroon 5 tracks, as well as the No. 17 song, One Direction's "What Makes You Beautiful."

At No. 6 is Downtown Music with 2.7%, which is the company's best showing in the five times it has made the top 10 rankings. Downtown placed seven songs within the top 100 radio songs. In addition to "Wide Awake," its next-best showing is Neon Trees' "Everybody Talks" (No. 9).

A single track can power a company into the top 10 if it's big enough: Simkins Artist Management retains a spot in the top 10 for the second quarter in a row, this time improving its share to 2.6% from 2.1% as its sole song in the top 100 airplay rankings, Carley Rae Jepsen's "Call Me Maybe," moved up to No. 6 from No. 9. Likewise, Jerk Awake Music also placed one song in the top 100-the No. 11 track, Demi Lovato's "Give Your Heart a Break"-to make its debut in the rankings with a 2% share.

On the songwriters chart, Shellback vaults to the No. 1 spot. Though he hadn't been in the top 10 during the previous two quarters, the Swedish producer/songwriter had a credit on six of the top 100 radio songs, including "Payphone," his highest-ranking track. Given his work on Taylor Swift's "We Are Never Ever Getting Back Together," expect to see him again when the fourth-quarter numbers are tallied.••••