Every November since 2015, and maybe before, the dead.net site has a contest that features 30 Grateful Dead downloads (one per day) with an option to guess the date and venue of the live recording. With the next day’s download, the previous day’s answer is posted.
Daily prizes are awarded and at the end of November, they offer prizes for the most correct answers.
While I have never actually participated in the contest I have downloaded all the recordings and saved them. By the end of November 2021, I will have amassed 210 free live Grateful Dead recorded songs for my music collection. It’s a great way to find and play random live Dead music. Do it and participate in the contest or just collect free music — you’ll love it.
To play go to: https://www.dead.net/30daysofdead