1981 Star Wars radio play
The whole 13-episode radio play has been made available as an archive here:
https://archive.org/details/StarWarsRadio/01+Star+Wars+01.mp3
I've been listening to it over the past couple of weeks while walking the dog. Ben Burt's sound effects and lots of extra scenes and dialog (especially at the start) make it well worth it. There's a great surprise moment from Tarkin towards the end. It's also been interesting to see how they address certain things in a sound-only medium.