Sounds of the Purple Finch

Purple Finches sometimes add the sounds of other species into their warbling songs. They mimic American Goldfinches, Eastern Towhees, and brown-headed cowbirds. The sound of barn swallows is their favourite sound to add in songs.

Purple finch songs are described as being musical warbles and during flight they make a “tick” sound. There was a time when they were kept as caged birds because of their pleasing song.
~ https://nextbirds.com/