It’s coming up on three years since the quick buzz around CBS Radio’s KAMP (Amp 97.1) Los Angeles helped spur a building boom of second CHRs in a market—many of them working from Amp’s musical template, more rhythmic than the incumbent CHR, but not quite Urban or even “Rhythmic Top 40” as that format was then defined.

The second CHR boom took place as Arbitron’s PPM ratings measurement was continuing its roll-out through the top 50 markets. The new stations were propelled by the then dominant thinking that “PPM loves cume, therefore PPM loves CHR” and quickly spawned a corollary, “PPM loves tempo” that impacted multiple formats. But the boom was also driven by stationswho were looking to leave other formats in flux—especially Rhythmic Hot AC and Rhythmic Top 40.

Of thosesecond Mainstream CHRs launched in February 2009, or later, there are only a handful of unqualified success stories now. Amp 97.1 itself is No. 3 in the market with a 4.6, despite the continued strength of rival KIIS. Cox’s WPOI (Hot 101.5) Tampa, Fla., is sixth with a 5.4, and has quickly proven itself to be a serious contender against WFLZ.

Only two other recently-launched second CHRs are clearing a four-share at the moment. One is Clear Channel’s WMKS (105.7 Hit Music Now) Greensboro, N.C., with a 4.9. The other, WNNW (Radio Now) Jacksonville, Fla., (4.1) is actually an adult-leaning CHR that moved away from the “more rhythmic than the other guy” template that it had helped foster more than a decade ago as WFKS (Kiss FM).

There are also two significant success stories that came into different market situations than Amp and its acolytes (Amp-co-lytes?). San Francisco’s KMVQ (Now 99.7) was arguably the first mainstream CHR in the market; however you count it, it’s No. 3 now with a 4.8, as heritage Rhythmic outlet KYLD (Wild 94.9) tries to lock down the “hit music” image itself. Likewise, WVHT (Hot 100.5) is at a 5.5 this month, ahead of Rhythmic WNVZ (Z104), which had doubled as the Mainstream CHR in the market.

More typically, the recently-launched second CHRs in their market are somewhere in the mid-teens in overall rank and somewhere in the 2.0-3.5 share range. Yes, there are 12-24 or 18-34 success stories that a 6-plus share or ranking doesn’t acknowledge, butthat doesn't necessarily translate to a good living. And the same can be said of the Alternative and R&B/Hip-Hop stations with similar overall shares that are considered less tenable in the PPM era.

This doesn’t mean that the new second CHRs haven’t had an impact on the CHR landscape. The addition of 15-20 stations, narrowly focused and with high spin counts, to the Mainstream reporting panel has made it harder for ballads to crack the top 10 or anything that isn’t Rhythmic pop to get traction. In Seattle, the second Mainstream CHR (KQMV) has pushed KBKS (Kiss 106.1) out of a unique position (fast on rock, and especially teen punk) and into a more typical CHR music profile.

In the early ’00s, when the success of Clear Channel’s medium-market, rhythmic-leaning “Kiss-FMs” had a similar effect on the charts, you couldn’t quite begrudge them. Many of them had ended up beating the “Modern AC with CHR reporting status” that had represented Top 40 in various markets before them. But in this case, the difference in the charts is being driven by three-share radio stations, not five-share stations.

Since February, 2009, Amp’s success has reinforced how different Los Angeles is from other markets. Its strategy of being more rhythmic than the already rhythmic incumbent likely stemmed, in part, from having Alternative KROQ in the building, long a station with some “pop CHR” functionality itself. But the hole between KIIS and KPWR (Power 106) proved to have few parallels in most other markets, and the “even more rhythmic” strategy turned out not to be the secret weapon it had been for the past 25 years.

In San Francisco and Norfolk, the Amp formula worked because there was no Mainstream CHR—positioning a station just to the right of the Rhythmic Top 40 was the right thing to do in markets where the right balance for Mainstream Top 40 had been elusive for several decades in both cases. Only in Tampa can you say that the second CHR found a place between Mainstream and Rhythmic Top 40 in a crowded market, and Hot hasn’t been campaigning against WFLZ’s music as much as its heritage morning show.

I'm always happy to see CHR expand. The biggestmissed opportunityof the Second CHR boom has been that it didn’t really develop a second way to do CHR. The late ’90s/early ’00s Kiss-FMs had re-shaped about 70% of the format around a “fast on rhythm/slow on rock” template. The new group of CHR stations took that strategy even further—looking for a wedge against the Kiss-FMs that had gone just a tad more pop over the last decade. Without in any way denying the legitimacy of today’s rhythmic pop, there’s probably still room for a more pop-leaning current-driven format that plays the other music enjoyed by young adults. But for now, that format is Country.