The three main radios in the cockpit (which are all exactly the same) are VHF in approx. band of 117.0 to 136.0 - they can tune in any station they want to the hundreth although most frequencies end in a 5 or 0. The pilot has one radio, the co-pilot the other and one is back-up.

All ATC communications, ground control, etc. take place over these frequencies including ATIS, which is nothing more than the recorded weather report from the airport updated frequently. Over water aircraft have HF - high frequency - radios on board. They provide very long range but scratchy communications that are very susceptible to solar interference.

The receiver they use to navigate to the VORs is also capable of picking up any AM radio station in the country.

For company communications they have something called SelCall, which I think stands for selective calling and is some sort of radio telephone set up. It just beeps when they have a call. They don't monitor it or anything.