The incomparable nature recordist Lang Elliott has produced a masterpiece of Hermit Thrush song, and you simply must listen to this work. Lang took an eighteen year old recording made by Ted Mack, and remastered it by slowing, stretching, stitching and compressing, and ended the melody with a flourish by a White-throated Sparrow (which was a background voice on the original recording).
Listen to Lang's Hermit Thrush aria RIGHT HERE. Keep in mind that complex tunesters such as thrushes and many other songbirds hear in ways that we don't, and Lang's remix may be far closer to what Hermit Thrushes hear, as compared to what our tin ears detect.
Check out Lang's and Wil Hershberger's always interesting blog HERE. You'll want to bookmark this bit of the Internet.