A small, rust-colored passerine (perching bird) fills the woods with rich melodies in minor keys. Their dissonant and eerily beautiful song slides sweetly through every staff line on the bar, ringing in the following silence until you find yourself aching for the sound.
They harmonize with themselves. Mammals like you and I have one opening in the airway to the lungs, called the larynx, from which we make sound. However, some birds, such as the thrush family, have something called a "syrinx". It's similar to the larynx, but instead of opening above the fork in the trachea, it actually opens at the fork, meaning these birds can make two sounds at one time. Because of this, they harmonize with themselves, not only each other.
The final note of the wood thrush song is a testimony to that. The flute-like tones that come before it are liquid and clear, but the final note vibrates harshly, quickly, like poker chips being thrown together; sometimes, it's slower, like the laser sound effect in movies, or like someone plucking a metal string that's been too tightly wound.
Right now, they're singing at all but the hottest parts of the day. It fills my heart with something wonderful.
I'm not posting a link for the song because you can find it online, but I encourage you to come listen to the wood thrush in person. Trust me, listening to it through speakers will never do it justice.
Photo courtesy of Lloyd Spitalnik Photos