Darlene Love performed it 28 times on David Letterman shows. This is a mashup of various performances.
This is the final one (when she was 73 years old):
This is the original recording – 51 years earlier!
Here are more versions from Letterman shows:
1986 (The first one) – it is so stripped down compared to the later ones!
There are even more versions of this great performance on YouTube.