Can you give a location or attempt to take a recording of it? The list of birds that make long melodies could go on for days. There are approximately 10,000 bird species in the world.

Male Great Tailed Grackle

Can you give me examples of birds (probably an exotic bird), which does a strange long melody over and over again early in the morning?

I think the whistling is coming from the nearby zoo, but when I wrote them an e-mail, I didn't get any answer.