The Grateful Dead played I Know It’s A Sin, the Jimmy Reed classic, only a handful of times. Well, they may have played it more in their first few years, but with spotty setlists from that era we’ll never know. Suffice it to say it was a rarity.
This is a slow, almost haunting blues number, but without the specters that inhabit a tune like Death Don’t Have No Mercy. Interestingly, both of these songs were sung by Jerry. It makes you think about they types of blues tunes that each member opted to sing. Each vocalist who took on the blues, Pigpen, Jerry, Bob, and Brent, all had different approaches. I think Bob’s changed, especially over the course of the 80s and 90s when he started to introduce more blues numbers. Maybe Jerry was just on a dirge-blues kick in the late 60s? You Win Again and Big Railroad Blues were more upbeat, but only the latter stayed in the repertoire for long period of time.
Two versions of this from April 1969 have made it to release, this one and the other on the Download Series, Vol. 12 release. Both are worth a listen.