A new study from Nielsen BDSradio finds that the perennial '80s acts heard on the AC format are giving way to newer voices like Katy Perry and Bruno Mars. The study of the evolution of the AC format in Canada finds that AC is "increasingly a song-based, not artist-based format."

Nielsen BDSradio's annual "Format Wars" session, presented last Thursday, March 22 at Canadian Music Week, highlighted the continued evolution of the Canadian AC format. It also looked at the Edmonton market, a year after it became a three-way CHR war, and unveiled new research, in partnership with BBM Analytics.

Nielsen BDSradio Operations Consultant Andrew Forsyth found that Canadian AC radio plays 20 percent more current music than it did five years ago. In addition, on average, music played on Canadian stations has become up to 12 years newer on some stations over that time.

Surprisingly, 63 percent of the top 100 most-played AC artists from 2007 are no longer on the top 100 list in 2012. Many of those artist, like Phil Collins and Rod Stewart, have found a new home on the Adult Hits and Oldies/Greatest Hits formats, which has taken ownership of AC's '60s, '70s and '80s music. While it was typical for some stations to play up to 34 titles by core artists, new acts like Perry, Mars and P!nk are typically represented by fewer titles.

Nielsen BDSradio Canada also reveals a new way to track listeners’ experience with music on radio using Infosys+Radio, a service of BBM Analytics. A study of CHR stations in Edmonton combined BDS airplay with PPM audience measurement, traditionally used in planning advertising schedules, to help track reach and frequency of the music they expose.

A look at Edmonton's three-way CHR race found that listeners of CFMG (Virgin Radio) would have heard Flo Rida's recent #1 hit, "Good Feeling," an average of 19 times over the last five weeks. Not only was Virgin Radio/Edmonton, with its tighter playlist and higher rotations, exposing the song more often to its own core audience, it was also the station where partisans of competing CHR stations were most likely to hear the song as well.

Nielsen BDSradio is preparing a similar report for U.S. radio.