Students often greet me with an astonished “how can you DO that?!” when I quickly work out or play back a melody or chord progression by ear. But there’s no supernatural gift involved, just a skill that can simply be learned.
Solfège puts the emphasis on the musical ear. In lessons and at home you train distinguishing chord types by ear, sight-singing, and recognising and reproducing intervals, in short, everything that belongs to ear training.
The ear can be trained to tell harmony apart, just as you train your fingers for playing the guitar. It takes some practice, but it brings a lot of enjoyment.