Mansoor Zalzal was the first singer/songwriter/guitarist
superstar--which is to say he played his oud and sang his songs in the Court of the Celebrated Haroun al Rashid--he died in or about 790, which, I guess, could qualify as very,very, early middle ages--at any rate, rather than being a theorist, he was a great player, and he refined fingering techniques which are the basis of a lot of what we still do on our axes today--

He claim to fame wasn't scales, exactly, but I am guessing that what Jack is talking is a note that he invented, called "The Wusta of Zalzal"--this is a neutral third, halfway between the major and minor----this is the note that some ethnomusicologists claim that the "Blue Note" is supposed to be--

I don't know enough about the Highand pipes to know if this is right or not, but I am taking it that Jack is saying that they feature a neutral third--a blue note!