According to Allaboutbirds, the Brown Thrasher has one of the largest repertoires of any North American songbird, up to 1,100 song types. Ours was playing its greatest hits but kept coming back to its version of the whip-poor-will, a nocturnal bird that has kept us awake during its breeding season. The other key to identifying the call was its repeating the song twice, then immediately starting the next tune while a mockingbird tends to repeat it three times.
The Brown Thrasher is rather distinctive with its long, slightly curved beak, long tail and a bright yellow eye that is prominent. They migrate up this time of year, extending all the way to Canada. There are reports of individual birds reaching Germany and England once each, probably on a foreign vacation. Lisa Berger came up with more range data: "
"They are listed as an uncommon Southern Missouri winter resident. Locally, we see them on Christmas Bird Counts, similar to E. Phoebe. These guys are more common in winter than my perception simply because they aren’t singing!"