I forgot to include the following sentence. I corrected it but I still have a doubt.
1) The poet says that the girl's song is more welcome than any chant of the nightingale to weary travelers in the desert, and that the cuckoo-bird has never sung with such a thrilling voice (or a voice so thrilling???)
What do the "weary travelers in the desert" hear? The girl's song? Or the chant of the nightingale?
The phrasing around "thrilling" can be either way; neither is wrong.