Years ago, I had the wonderful opportunity to go be in the studio audience for NBC's The Sing Off, which was an acapella competition show. All of the groups were talented, but one of them was noticably that much better. That was pretty clear from the moment they opened their mouths, regardless of which song they chose. By the way, they ended up winning the show that season!
Fast forward to the present. That sensational group has since lost a member (who chose to bow out) yet continues to churn out gorgeous instrument-free harmonies. You've heard Camila Cabello sing "Havana" plenty of times on NOW 105.7 and even though this is the same song, the group's take on it is wildly different. That mouth-trumpet solo at the end? Totally nuts!
Watch this thing once, twice... maybe thrice. It's really that good.