rock and alt rock are both very weird formats, you have some in both Rock and Alternative Rock formatted stations that will outright play new music from bands like Ice Nine Kills and I Prevail, very popular when you look at streaming services but they don’t have the same wide spread appeal.KNDD in Seattle seems to be adding more hits from the 80s due to KPNW being around I believe.
A few of the major markets like Philadelphia’s WMMR play a lot of modern hard rock
I’m not sure how “alternative” is supposed to differ considering small markers have modern rock only, something like Sirius XM’s octane.
It seems like Rock stations add either modern rock or classic rock to fill format gaps (ie: no classic rock competitor) when they’re not formatted specifically to be classic.
On a similar note I’ve been complaining KSAN needs to try that for a while.