I've never understood why sometimes people raise this "issue" but stop short of saying anything about "Grande." A Texan once heard me sing "Rye-o Grand" and corrected my pronunciation -- as if I weren't a fellow American who knew exactly how we currently pronounce the name of the river in English! ("Rio Grand") I said, "So... what about the 'grande'?"

Also: Are you aiming for a Spanish pronunciation or Portuguese?!

Rye-o is one old-time pronunciation by ENGLISH speakers.

We see Rye-o in evidence on the majority of recordings -- tying this pronunciation to the song (i.e. whether or not the pronunciation was common in speech). It's a localized pronunciation; prescribed pronunciations according to grand(e) concepts of standard languages don't apply.

(Just returned from 'Owhyee' (Hawai'i), was in Hilo (not pronounced as in chanties, and nothing to do with chanties). Home to the island of "Mowee" -- a spelling which would probably lead English speakers to capture the native pronunciation better than the contemporary spelling, "Maui.")