Furthurmore Friday Week 35

For the 35th Furthurmore Friday, we had the following contest:



After seeing the film "Saturday Night Fever" in early 1978, the Grateful Dead playfully fooled around with this Disco hit from the movie during tuning breaks at a couple of shows later that year. What song was it and provide the date of one of the shows it was played?

Of the first ten correct answers (Stayin' Alive, on 4.24.78, Normal, IL),
Chris D. was chosen at random and won a Furthur 2010 Radio City poster.