I have a very talented catbird this year. He has been singing incessantly since spring. He has a favourite perch overlooking my backyard and delivers his versions of:
American Goldfinch
House Finch
Pine Siskin
Red-eyed Vireo
Chimney Swift
European Starling
Red-winged Blackbird
Brown-headed Cowbird
Ring-billed Gull
American Robin
Wood Thrush
I am sure there are many others I don't recognize or have forgotten. I should get around to making a recording of him. His Pine Siskin and Ring-billed Gull imitations are pretty impressive and I'll give him a 10 out of 10 for his version of a Brown-headed Cowbird.