A Little Help, Please

I just read this (italics mine) in the NYT's review of the Fugees' reunion concert in the Big BK:

"Then it was Ms. Hill's turn, starting with, 'Killing Me Softly With His Song': she sang the first verse nearly a cappella..."

What does "nearly a capella" mean? Was she accompanied by only one instrument? Or did someone play a few notes and back off?

I'm confused.