Oor Hamlet (aka The Three-Minute Hamlet) was written by Adam McNaughton of Glasgow, Scotland. It was recorded on McNaughton's album Words, Words, Words which is apparently long out of print. Here's what McNaughton has to say about the song (taken from the liner notes of that album):
"The first 'act' of Oor Hamlet was written when I was reading the play with a fifth-year class at Cathakin High School. It then lay untouched for a year, until I saw a letter in 'Sandy Bell's Broadsheet' which I felt overstated the case for singing more ballads in folk clubs. The writer, Sheila Douglas, had made a comparison between the plots of the ballads and the plot of Hamlet. This proved to be the stimulus I needed and I finished off the 'poem' very quickly. Even before I sent it off, however, I realized with slight amendments and additions it could be sung to the tune of The Mason's Apron."