Please Help Me!

I heard some guy in a car today blasting this one song. I couldn't really catch the lyrics, except the chorus. And I never knew who sang it, but I heard it when i was younger.
It's a 90's (early im guessing) R&B/Soul song. I know the chorus goes something like; "Ahhhh Ahh Ahh Ahhhh"
It's not being screamed incase people think the "ahhh" is being screamed. And it also isn't Earth Song by Michael Jackson which has the "Ahhh" type of chrous.
It's presumably sung by a black man/group. Has a Shai type of sound. And I'm not sure if it is acapella, but the music definately isn't overpowering the vocals. If anyone knows a song that fits this description, please help!
I asked some friends and one of them suggested "Uhh Ahh" by Boyz II Men, but it isn't.
PLEASE HELP!

Anyone!?