Our ear is an amazing organ. Usually after hearing a song a few times, we can sing it right back without ever knowing what notes we're singing! But as songs get more complex, it often helps to have a more definite sense of the pitches. The Solfège system (think Do Re Mi as in "Doe a Deer" from The Sound of Music) provides a great framework for training our ears and voice to do exactly that. With practice, it helps with sight-singing (singing directly from sheet music), confidently singing harmonies, and understanding basic music theory without ever touching an instrument.