Parking lot bird help
I cannot describe my amazement by this bird. Never really been fascinated by birds but after hearing this bird at work I'm dying to know more about it. First I do not have a picture, but think it could be identifiable, it is from the Cleveland Ohio area, urban area. It has this amazing, seemingly never repeating bird call that changes every 10 seconds or so. What may typically be described as a car alarm bird. I heard it do about 7-8 completely different calls and then fly off. When it did, the only striking feature was some unique white shapes on the underside of its wings. Other than that, it was a non descript average looking bird, maybe 7 inches tall, dark color brownish black maybe.
Any help would be appreciated, Thanks,