I have edited 8 recent updated vocal styles for SMP. I found there are three types of Mega Choir in T4 and later top level keyboards.
1. *aa, 2. *oo and 3. *ee.
For *aa I replaced BoysAah, GhoticVox and Choir (Legacy).
For *oo ... BoysOoh and UuhChoir.
But for *ee, I put Aah and Ooh alternatively in previous updates. Now I changed HaaChoir (000-114-053) for *ee, it sounds different. You can hear clearly in the Intros and Endings of 'TheJazzSingers' (Swing&Jazz).
With these changes now I edited 8 styles up to Swing&Jazz.