He's been very open about his struggle with Tourette's Syndrome and over the weekend while performing at Glastonbury Festival he wasn't physically able to finish Someone You Loved.
So the audience took over for him and it was a remarkable moment. The frustration and disappointment on Lewis' face was matched in spades by the love, compassion and understanding emanating from his audience.
I dare you to watch this and not cry.
He's had to cancel the rest of his upcoming tour which has got to be heartbreaking. Here's some of what he said: “I used to be able to enjoy every second of shows like this and I’d hoped three weeks away would sort me out. But the truth is I’m still learning to adjust to the impact of my Tourette’s and on Saturday it became obvious that I need to spend so much more time getting my mental and physical health in order, so I can keep doing everything I love for a long time.”