When I drive around the Sequoyah National Wildlife Refuge in Oklahoma the Red-winged Blackbird is one of the main birds I see and hear. You can get close to these birds if you remain in your vehicle.
I was able to get a closeup of this Red-winged Blackbird singing a few days ago. I was photographing a family of Geese when it flew a few feet from my pickup and began singing.
The calls of the red-winged blackbird are a throaty check and a high slurred whistle, terrr-eeee. The male's song, accompanied by a display of his red shoulder patches, is a scratchy oak-a-lee, except that in many western birds, including bicolored blackbirds, it is ooPREEEEEom. The female also sings, typically a scolding chatter chit chit chit chit chit chit cheer teer teer teerr. (Source: Wikipedia)
Red-winged Blackbird Singing - Sequoyah National Wildlife Refuge - Oklahoma