Like Thriller, this record was a massive mono-culture presence that just doesn't exist anymore in music. It was everywhere for a year and a half - if you didn't like it, too bad because you were going to hear it coming out of every other car radio and storefront.
I always thought the Bee Gees were underrated as artists. Their stuff in the 60s/early 70s was really weird, even though it sounded kind of like a discount Beatles. And their mid-to-late 70s peak was full of great pop goodness, done with skill and talent. They also made half a dozen other artists' careers.
All that said, the best song on this record IMHO is the incendiary and aptly-named "Disco Inferno". The bass line is iconic, of course, as are the swirling brass-&-strings. But what makes the record, to me, is Jimmy Ellis' Voice Of God lead vocal. Other than P-Funk and one or two others, most bands then that were playing dance music in the late 70s went for smoother vocals. Jimmy said" screw that" and went full-on Edwin Starr/Wilson Picket. That tension between 60s-style soul singing and the more streamlined playing of the band makes it one of the most exciting records of the late 70s