Ron Isley and the Isley Brothers are one of the best. Not exactly Curtis Mayfield and the Impressions back in the day, but Ron Isley still pumps. He was able to adjust to every decade since the early 60's. He even got a big hit out now. His recent duets over the last 10 or 15 years where also off the charts. I know no other vocalist that can do this like him. He can still take his Isley Brothers style, and adjust with any modern style or genre, and still record a smash hit. Although he's popular, I think he has been very underrated. But I do remember back in that 70's, when they didn't sound to well live. But not too many groups did, including the Ohio Players. But technology changed that.