Hello! I live in the mountains of East TN. I have a wily little bird who comes around in the spring who has a two-note song that sounds like a man wolf-whistling at a woman! It is a slow whistle with a high note and then a slow dropping tone. There are several seconds between the whistles. The first note is similar to a cardinal song start, but I don’t think it’s a cardinal. It is a small bird that hides in the gray branches. I have listened to several recommendations, but none are my bird. I’m starting to think it’s a truncated call or maybe just a springtime mating call. I will search until I find him! LOL