Some event web pages have links to let you add the event to your calendar. They use a variety of techniques to do so.
When I click on, for example, Great American Sing-along, which seems related to the ActiveDataExchange product, using Chrome, it just offers to download a file "adecalendar.ics". Firefox offers the same option, and also offers to let me open the file with an app of my choosing, but only shows emacs as an option. And kitchen-sink though it may be, by default emacs doesn't seem to do any magic with .ics files ;)
I know that if I save it to a file, and go to https://www.google.com/calendar I can import a .ics file, but that involves a lot of frustrating steps.
So how can I just get a one- or two-click method of adding this to my google calendar?
Note that if the web site offers the calendar via a "webcal:" protocol, it is possible to configure a protocol handler so that gets passed off to the google calendar site, as documented at Google Calendar as default handler of webcal protocol for iCal/ICS files.