From the book

“At close range, you’ll hear soft bup bup notes preceding his loud, flute-like ee-oh-lay, followed by a rough trill . . . Listen to the next song, and the next, and you’ll seemingly never hear two alike. But pick a distinctive ee-oh-lay, and you’ll hear him return to it again and again, as he has three to six of these introductory notes . . .”

Listen to the 14 songs in this one-minute sequence; pick out the soft bup bup notes at the beginning, the loud ee-oh-lay, and the rough trill on the end of each song. Concentrate next on those ee-oh-lays; listen to this sequence a few times and you may come to realize that he has a set pattern in which he uses those ee-oh-lays, the sequence in these 14 songs being A B C A B C A B C A B C A B.

From the book

“And what we wouldn’t give to hear these songs as the Wood Thrush no doubt hears them. Perhaps he hears it something like we do when we slow the songs to one-tenth the speed . . .”

Listen here to the first three songs in that sequence slowed down to one-tenth of normal speed.