The |É‘| is, as you know by now, the sound that comes out when we get that lovely deep, low, relaxed space in the throat.
Think of it as the foundation vowel. It is the position on which you build your whole voice. All other vowels are produced within the overall envelope of this foundation position. Loke a big box which contains many other boxes.
It is this foundation, and the way every singer has a slightly different foundation, that plays a major part in giving each singer her or his unique and recognisable tone.
Later on we will come back to this concept when discussing styling and 'moveable foundation.' It's gonna rock your world!
(REFER video of London Grammar and Annie Lennox Why on YT playlist... similar sound due to similar throat shape.)