Vowels are the means by which we unify choral sound. They determine pitch and are the primary determiner of dynamic volume. If they’re enunciated consistently between singers, they also express the unity of the entire ensemble.
It’s necessary to agree on how we’re going to sing our vowels. I’ve found that the most reasonable choice is to start with the “Latin” vowels as a baseline, because using them makes it relatively easy to get everyone on the same dictional page.
If you try to smile a bit more than is comfortable while singing, this produces “wide” vowels. Singing with a wide vertical separation between tongue and palate produces “tall” vowels. Both ends of the spectrum have their uses, but not everyone can get to both extremes. So it makes sense to have everyone start from somewhere closer to the midpoint as a default/baseline position.
Singing at the midpoint unifies the choral sound by minimizing the range of differences between voices. Vowels will be more uniform across the ensemble, and that means better diction and communication with the audience.
