Open a window or step out doors and you are sure to hear bird song. When driving around town with my window down, I hear many distracting melodic sounds. Most often it is a Dark-eyed Junco trilling away or an American Robin singing a variety of songs that carry quite a distance. In most cases, these two birds are perched high and are easy to spot.
I was recently told a story about a couple of birders who heard an unfamiliar song. They stopped to look for the "rare" bird that had to be hiding among the branches. With a little patience they got a look, and it turned out to be several Boreal Chickadees singing a new tune.
Even though chickadees often have very distinct songs that make them easy to identify even when unseen, they also have spring vocalizations that are different from the rest of the year.
As I have said before, identifying bird songs is quite difficult for me. Sometimes, I don't hear the high-pitched sounds and many times, I can hear them but just don't have the musical memory to retain the patterns. Perhaps part of that has been related to my concentrating so hard on just identifying the bird when I see it. There is no doubt in my mind that this year I know a great deal more about the small woodland birds than I did last year.
I still get excited with each little bird that I see, but maybe this year I won't be like a child on an Easter egg hunt, flitting from one find to the next. I intend to stop, look, listen and learn. There is surely more space left in my brain for new information.