What does that mean to you? How does it sound?
Hmm well of course it is just marks on your screen so doesn't sound like anything until you say it out loud. Depending on many factors including where you come from and how you are feeling right now you could choose to sound out that small two-letter symbol in any number of ways. I could try to be more specific and give you the example of a word, like for example "Father." Still, the same problems apply.
So who cares anyway>
Well if you are trying to sing well, you should care. Imagine for a moment you are not a singer but a saxophone player. You go out and spend two grand on the best sax you can afford, real world-class. Then you sling it in the back of the van with the PA speakers, and of course it picks up a few dents. But again, who cares, it'll play just fine bent out of shape... won't it? After all who knows why they make saxes that wierd shape, maybe just to look good..?
No it will not play right. The shape of a sax is largely what makes it sound the way it does. Even the smallest ding will have an adverse effect of the timbre, pitching, stability, and ability to hit the high notes. Sounds familar, right? Starting to figure where this is going?
Yes, it's all to do with the laws of acoustics, which we can't change. The body of the sax is the "resonator" which has a particular effect on the sound waves coming from the reed - something about "standing waves" "formants" "harmonic series" and so on. The end result of all this acoustics malarkey is the timbre we know and recognise as the saxophone.
So the spaces and shapes in the vocal tract do the same kind of thing to the sound waves coming from the vocal cords. And the exact way we say the vowel creates the shape of the resonator... which as we know should not be dented or twisted out of shape in any way. So a pure vowel = a pure sound, great timbre, accurate, stable pitch, and easy range.
Next time we will look at what we mean by pure vowels, how we find them, and how we use them in real-world singing to create any style or sound.