When the then-Clear Channel Radio unleashed its suite of Kiss-FMs in the late ‘90s and early ‘00s, it was hard for the template of stations such as WAKS Cleveland and WKST Pittsburgh not to set the tone for the entire CHR chart.

The new CHR stations played Rhythmic Pop, Hip-Hop and an occasional teen punk or Linkin Park record with ultra-high rotations (then around 90-100 spins) on power rotation. Their old competitors played a more adult-leaning blend, usually with far fewer spins. And sometimes, when one of the new-model CHRs showed up and blew a hole in the market, the other CHR station would just get out.

One of the reasons the incumbent often left was not wanting to follow the Mainstream Top 40 charts, especially if that meant playing Eminem and DMX on a station that had been Sheryl Crow and Matchbox Twenty until that time. The charts became a self-fulfilling prophecy. The stations that leaned rhythmic were contributing far more spins per capita. The stations that leaned pop were leaving.

I’ve been thinking about that type of chart impact since KKHH (Hot 95.7) Houston and WZMP (Amp 96.5) Philadelphia changed format shortly after the beginning of this year. In 2008, it was Hot 95.7 that began the boom in second CHR stations. The next year, CBS launched Amp 97.1 Los Angeles and Now 92.3 New York and suddenly the industry was less daunted about going CHR against Clear Channel.

Houston, Los Angeles, and New York also created a template that spread beyond CBS and became typical of second CHRs throughout the industry. Even higher spins — sometimes up to 140x a week on powers. Usually, the second CHR was rhythmic-leaning and even more tightly focused than the typical fast-on-rhythm/slow-on-pop/rock Clear Channel station. If Churban had found the spot between Urban and CHR, the new stations were lodged between an already rhythmic-leaning CHR format and Churban.

Typically, a research project for a new radio station will test somewhere between ten and 20 music styles in hopes of finding a half dozen that work well together. The new stations often felt as if they had committed to three music styles: mainstream pop (of the Justin Timberlake/Justin Bieber/Selena Gomez variety); rhythmic pop (R&B and Hip-Hop-flavored, but not necessarily what Urban played); and dance/pop, back when it hadn’t yet become “EDM” in common parlance.

The new stations were, essentially, rhythmic pop. If they had reported to the Rhythmic Top 40 chart, they would have given that chart a new clarity — rather than a wide spread of stations that ranged from very pop to essentially Urban. Instead, they became part of the Mainstream Top 40 chart and eventually, most of Rhythmic’s more pop-leaning stations moved there as well. Because the new stations weren’t that different from former rhythmic reporters such as WKTU or WPOW (Power 96) Miami or WBBM-FM (B96) Chicago.

In the 8-1/2 years since KKHH’s launch, the distinctions between the challengers and the incumbents have blurred. When Now 92.3 debuted in New York, rival Z100 had the ingenious strategy of maintaining its pop lean musically and letting sister WKTU engage with the newcomer on the rhythmic front. But it was inevitable that the stations would draw closer. Z100 played its top “power rotation” song 122 times last week. WBMP (Amp 92.3), the rebranded Now 92.3, was at 128 spins. KIIS Los Angeles (114 spins) was only a few short of Amp L.A. (120 spins on its top power).

The distinctions between the genres have narrowed too (as exhaustively chronicled in the ROR column, I admit). Justin Bieber’s “Sorry” goes in the pop stack; you might put his guest vocal on Major Lazer’s “Cold Water” or DJ Snake’s “Let Me Love You” with other EDM/pop songs. But that’s a function of which artist name is first, not a significant difference in music style.

At this moment, we find ourselves with the most claustrophobic CHR format in nearly 15 years. And without the consolation of being able to say “somebody must like the music, because the format is winning.” At holiday time, it’s nearly impossible for a CHR to lead the market in PPM. But in the first two days of Nielsen PPM ratings, only one CHR (KQMV Seattle) is even No. 2 overall.

And surveying the format now, one wonders if CHR could have possibly avoided its current narrowness. Because if even a quarter of the format is narrow musically, and spinning songs in high rotation, then the favored genres of music are inevitably going to have a chart advantage. Other music styles find it hard to get a quorum, although there have been hard-fought and passing exceptions (Mumford/Lumineers, the spate of piano ballads of a few years ago, Elle King).

When CHR was driven by “turbo-pop” — “Dynamite,” “Party Rock Anthem,” “Raise Your Glass,” “Only Girl in the World,” “DJ Got Us Falllin’ in Love” — it seemed like the new stations had steered CHR in a pretty agreeable direction. But the homogeneity of 2017 isn’t as appealing as the uniformity (if it was indeed such) of 2010. And these days, it’s hard to tell which stations are hewing to a deliberately tight recipe and which just don’t have anything else to play.

There is no intended rancor toward the architects of second CHRs. It was their duty to carve out a place in the market. I appreciate CBS Radio as an operator, and for their commitment to new music, and I’m sorry to see them vacating the format anywhere. There is also no swipe intended toward my former colleagues in the business of putting together chart panels — trying to steer the whole industry to a consistent vision of who should be on what chart is a painful task that I don’t miss.

But if segueing between two chirpy, midtempo tropical house records that both sound like “I Took a Pill in Ibiza” is in any way not fine with every CHR programmer, it will take an act of will from both programmers and labels.

In the early ‘90s, CHR had to nearly implode before a new group of stations changed the musical menu a few years later. I liked the early ‘00s rebound better. In that one, Clear Channel’s Z100 New York deliberately began looking for pop records; after about six fallow months, it suddenly had Kelly Clarkson’s “Since U Been Gone.” Changing a nearly monolithic chart will take a similar type of determination now.

Click Here To Subscribe to the weekly Ross On Radio Newsletter.