I have to imagine this question has been asked before, but I can't seem to find anything using various searches on the forum.

Is there any way to know ahead of time which frequencies a controller might use prior to them coming online?  It would be good to have a list (even if there are multiple frequencies used for a given controller at a given airport) of commonly used frequencies.  I've tried to match them up with those on airport charts and supplements, but with limited success.

 Where this would be useful is a situation where you are on an inbound course to an airport, and an approach or tower controller comes online.  You might be already engaged in something, and scrambling to jot down/enter your comm freq.  and make contact with a controller you didn't know was coming.  If you had a freq. ahead of time, you could be somewhat prepared.

The second question I had was in the event there are multiple controllers for a given function, say APP.  You might see 2 online, and not sure which one to tune to (in the event Center is offline and no hand-off).  I have always gotten a message "Please contact me on XXX.XXX freq.", which works, but if I knew which one ahead of time, I could be better prepared.  This happens in real life at busier airports, I understand, but again - if the frequencies don't match what I see on the charts, and the naming convention doesn't make sense to me, I'm not sure which one to be prepared to contact.  Is there somewhere this is explained?

Thank you,
William Kirkland