Ron Isley -- part of the famed group The Isley Brothers -- knows what he likes between the sheets ... a sex playlist with his biggest hits!!!

We got the R&B legend in New Orleans and our photog asked him for musical suggestions on how to set the mood on Valentine's Day.

Ron says Sade and Beyoncé are a couple good choices ... but what really gets him and his wife off is the sound of his own voice!!!

Some artists don't like to listen to their music when they get freaky, but not Ron ... telling us Isley Brothers hits like "Between The Sheets" and "Contagious" are some of his go-to joints.

The guy's got his own whiskey brand too ... so yeah, he knows how to have a good time in the bedroom.

It's a fun, and informative conversation ... check it out and take some tips from Ron before your Valentine's Day!!!