Although crows can make a wide variety of calls, you can hear the typical “songs” of American Crows here; scroll down to the “typical voice” section.
Also noted in the master article, crows have been observed dropping nuts onto a road, waiting for traffic to clear, and then gathering the smashed bounty. You can see a short, delightful video of this behavior, narrated by David Attenborough, bym a species of crow in Japan here.
You can learn a lot more about this intelligent, interesting species and some of its close relatives from a recent episode of PBS’s Nature—available in its entirety for your viewing pleasure here. Be prepared to be amazed!