Fan generated art for non-existant Adele singles.

As sales for Adele's "21" continue at extraordinarily lofty levels, radio is digging into the album to find more hits, even though Columbia Records is not officially promoting any further radio singles from the set.

The album's "I'll Be Waiting" rises 30-29 in its second week on Billboard's adult alternative Triple A radio airplay chart. "Turning Tables," meanwhile, ranked as the No. 18 song on Cox-owned mainstream top 40 WBLI Nassau, N.Y., in the July 23-29 tracking week, according to Nielsen BDS.

Adele, Gotye Lead Mid-Year SoundScan Charts

That stations are playing songs not being promoted by a record label not only harkens back to a time when programmers, in an era before multi-tasking and oversight of multiple stations, had more time to spend on searching for potential hits, but it also reinforces the uncommon staying power of Adele and "21."

The set ranked as the top-selling album of 2011 and remains in the lead as 2012's best seller. The album has sold 9.6 million copies to-date, according to Nielsen SoundScan. "21" has spent its first 75 weeks in the Billboard 200 top 10, a record among women, and logged 24 weeks at No. 1, the highest total in 27 years.

Columbia has officially promoted four singles from the album: the Billboard Hot 100 No. 1s "Rolling in the Deep" (Billboard's top song of 2011), "Someone Like You" and "Set Fire to the Rain," as well as the No. 16-peaking "Rumour Has It" (which reached No. 1 on Triple A last year).

How has "Waiting" stealthily found a home on triple A airwaves? "Programmers have asked if we're going to release another single from, '21,' but we don't want to burn Adele out," says Lisa Sonkin, Columbia VP of triple A and public radio promotion. "We want them to be salivating for the next album.

Historical Analysis: Adele Matches The Beatles, 50 Cent With Hot 100, Billboard 200 Moves

"So, we decided not to send out promo copies and promote 'Waiting' all-out. But, we're certainly not discouraging airplay."

KTCZ Minneapolis played "Waiting" 52 times in the July 23-29 tracking period, with WTTS Indianapolis (27 plays) and KBCO Denver (25) also on-board."I love the song and, given the strength of the album's other hits, I wanted to give it a shot," WTTS PD Brad Holtz says.

"Early research on our end has been very positive. I'm glad we put it in."

Sales, too, back up audience appeal for "Waiting" and "Turning." "Waiting" has sold 89,000 downloads and "Turning," 718,000, according to SoundScan. The latter title received extra exposure courtesy of a cover by the cast of Fox's "Glee," featuring Gwyneth Paltrow, last year. The "Glee" version has sold 114,000.

"If Columbia worked 'Turning Tables,' it would be a top five record," WBLI PD Jeremy Rice predicts. "It's a callout smash and a great song. Last time I checked, Adele has a pretty good track record. If you see an opportunity for your radio station to win, you go for it."

While radio takes an old-school DIY approach in spiking album cuts from "21," Columbia may soon have new music from Adele to promote officially. The singer, who announced on June 28 that she's pregnant with her first child, told NRJ Radio in April that she'll have "a new song probably coming out at the end of the year." It may not necessarily be from a new studio album, however, as, well, rumor has it that she could record the theme to the next James Bond film, "Skyfall," due in U.S. theaters on Nov. 9.

Additional reporting by Keith Caulfield

Questions? Comments? Let us know: @billboardbiz

Print