Hi Sean,
I finally had time to work with this. The following script will add a sound allarm 1 hour before every event in a particular calendar:
tell application "Calendar"
tell calendar "MyTestCal"
repeat with this_event in every event
makenewsound alarmatthis_eventwith properties {trigger interval:-60, sound name:"Basso"}
end repeat
end tell
end tell
I didn't add any error checking, but it should work if you have a calendar with events. Remember to change the name of the calendar from "MyTestCal". The "make" command in the first script posted didn't allow for multiple events, so I had to use a "repeat" loop.
You could add this to an automator workflow, but since you only need it once, I'd save it as an application from the Script Editor. Save the application for the next time you might need it.
ps. I wish I knew how to post scripts.
gl