Brigadoon has some of the prettiest music ever written for a show. Some of it may seem "old" or cliche by now (I mean, Almost Like Being In Love is nearly as ubiquitous as Memory), but songs like "Come to Me, Bend To Me," "There But For You Go I," and "Waitin' For My Dearie" are simply beautiful when done well. Frankly, I'd question your taste if you didn't think so.
And who cares how authentic to Scotland it is? The King and I isn't exactly the most "Siamese" sounding show...
You pretty much have to toss authenticity out the window as soon as you decide you're doing a musical anyway.
Hi, Shirley Temple Pudding.