When I first saw one at my feeder I was so excited! And since that first visit I only need to hear them sing to know one is in my yard. It's a distinct call; very different from the ongoing medley of finch and sparrow song.
I have a pair of red-winged blackbirds who visit my feeder, most often just the male. Sometimes his girlfriend stops by, but it's almost never a "date" as they usually visit the feeder solo. I've read that these birds are polygynous (meaning, one male bird mates with many females), so the female I see might be one of several girlfriends. Out for a quick meal away from the sister-wives. Kind of like the Big Love of blackbirds.