I thought I had ID'd a Lincoln's (from a photo) earlier this summer in another forum but I was wrong. An expert weighed in and pointed out the size of the bill. It was a juvenile Song and they certainly are variable. The stout bill of the Song, though, is quite different from the slender bill of the Lincoln's although so many other field marks are similar and the photo quality is always a factor. I believe this is a Song but the Lincoln's are starting to come through.