Thank you for your help last time.

I know that Disco Demolition Night was an event that took place in July 1979 in Comiskey Park, IL, and next year's the 40th anniversary of the event.

Would this be considered the catalyst for the decline of disco into the 1980s and the start of rebranding disco as dance music, even though it was de facto disco music?

When would you say was the start of the period disco fell into decline culturally and became the subject of jokes and public hatred? [I was born in 1986, so didn't grow up with disco that much, more Wet Wet Wet and new wave 80s bands].

In terms of finding primary and secondary sources for this, how easy would it be to find both, and are blogs about this on blogspot, wordpress.com a tertiary source? Where do the lines on primary/secondary sources get blurred, based on information from the eras?

What should I look for when examining sources about these? How would I find a primary source for this [being in the United Kingdom, it's harder to find primary sources, except maybe online].

Since listening to Earth, Wind and Fire; America; Doobie Brothers, I've started to look at 1970s music culture as something to investigate historically, for personal interest. I'm looking more at culture and fandoms, than the music itself and music history [so it's partially related].

This isn't a homework help request, but just general historical interest.

I would appreciate it if any historians could help me, as although this may not be as significant as, for example, the Cold War, it is significant form a social perspective.