Five-year-old Rock 100.5 announced that "big" changes are coming Friday at 10 a.m.

Word on the street is the station is going to start skewing younger by adding some of the music from the Bone and cutting back on classic rock. This way, Rock 100.5 can differentiate itself from 97.1/The River, the only other major signal rock station left in the market since Dave FM and Project 9-6-1 disappeared last fall. The River, while younger sounding than its earlier years, is still heavily 1970s and 1980s rock though its playlist is far deeper than it used to be.

How Rock 100.5 is teasing the change: "Two great things will become one," according to Atlanta Radio Insider, a blogger who tracks Atlanta radio.

And 98.9/The Bone's Facebook page teases: "Getting a whole lot BETTER Friday morning."

What will the Atlanta-based company do at 98.9? Cumulus has created a Facebook page for 98.9/The Walk. What format would that be? A Dave-like adult rock format could fill a gap in the market, albeit on a weaker signal than 92.9, now sports talk. It could also be a trick just to throw people off.

Cumulus has not killed off its old alternative rock 99X website either, with the phrase "Still under construction, dudes." It's possible they may just bring 99X back at 98.9. That station disappeared last fall when 98.9/The Bone was created in response to Project's departure. The Bone currently is a merger of Project and 99X music.

UPDATE: Another rumor: that Cumulus will pick up the syndicated Nash Country that just debuted last week in New York on 98.9 (or 97.9). Because, of course, metro Atlanta really needs another country station. Well, not really but who ever said radio programmers in this market are nothing if not repetitive? (See sports talk, pop, hip hop) And it makes almost no sense for Cumulus to cannibalize its own country station Kicks 101.5 (Then again, they do have Q100 at 97.9).