It's the only way to sightread. A new choirmaster arrived and taught tonic solfa to the children's choirs first, then to the reluctant adults who became less reluctant as they heard how it helped their kids learn their own parts on a hymn. I never want to go back to waiting while each part is repeated on the piano and learned by rote. We rehearsed a capella with solfa and then words. Helped our intonation immensely due to better awareness of the tonic and the relation of every note to that rather than just to the previous note.