Too many young'uns on this thread. If disco was your parents' music, this thread is not for you.
That said, I have two favorite disco memories.
The first one is from the very first time I went into a gay bar. Oh, how thrilled I was to sneak into The Fidler (Lancaster, PA) when I turned 18!! And no sooner did I get past the bouncer that a song came on that I'll never forget: Midnight Love Affair by Carol Douglas. It lasted 20+ minutes. Between the music and being surrounded by gay people for the very first time, I felt like I had died and gone to heaven.
The second memory is from when I was stationed in Germany. A fellow gay soldier took me to Frankfurt to go to a gay bar that was hidden in a basement. The door had a sliding wooden peephole just like in the old speakeasy movies. It seemed so clandestine, and at the same time, made me feel oh-so-"cool" to be at such a place. ["Coolness" was the watchword when I was that age. That was always the goal -- to be "cool."]
We went downstairs and got situated, and the next thing I knew, I was hearing the beginning of MacArthur Park by Donna Summer, the slow part. Couples started to slow dance. I had never heard the song before (it was early 1978), and when it suddenly changed to a disco beat, I also felt my soul sing. I was 19, and I felt like I was home. Finally.
For the young people reading this, being gay back then, especially in a small town, meant sneaking around to find bars where you could meet other gays. Everything had a tinge of "Oooo! I might get caught!" to it that made going out to clubs fun in a way it's not today. Now, you can easily find out about gay clubs, events, parties, etc. But then, I had to do a road trip to Philly to sneak out of Giovanni's Room (Phila. gay bookstore) with a copy of the Philly Gay News tucked securely under my arm. [And CBT in THAT paper meant "cock and ball torture" and not "Cognitive Behavioral Therapy."]
I know it doesn't seem like that to you young'uns, but it really was a magical time.