This has always been a very special disc to me; it has always entranced and impressed me, I must have played it 100s of times over the years. Cowell is one of my favorite composers and his contributions to 20th century music and indeed music in general, cannot be overstated. He was such an innovator, so influential and such an individualistic figure that I urge everyone who isn't familiar with his background and contributions to read up on him, whether a simple google search or visiting any number of classical site or forums that exist.
While many composers use actual folk melodies on which to base their music, it's an entirely different matter with Cowell. As a composer he completely understood the components of folk music and could compose in that language without utilizing any literal themes. That was one of Cowell's great gifts, and not limited to one folkloristic source, but to such sources of many cultures. Cowell's "Persian Set" was the result of a trip to Iran, at the special invitation of the Iranian government where The Cowells spent the winter in Tehran. Iranian music contained properties which Cowell had not encountered before, and he spent several hours a day listening to the traditional & classical music. Soon after he set to work on a piece which expressed the characteristics of of Persian and Iranian music. He used not a single actual Iranian melody or rhythm, or imitated them exactly. Persian Set is scored for a small orchestra, the Tar (a small double-bellied three-stringed Persian instrument), percussion, and voices (the kind of "vocalists" one might hear in some 3-5 person Iranian ensembles). This work from 1956 was ahead of it's time in many ways. The "Hymn and Fuguing Tune" (in this case for Strings) of 1944 was inspired by the great New England "shape-note" hymn composer William Billings. It is one of 18 compositions bearing that title, works representing Cowell's ideas of how early American sacred music might have sounded had it been developed steadily until the present time. This modal-folk like piece is simply gorgeous. "American Melting Pot" pays musical tribute to the different ethnic traditions that have come together in the modern United States. It was composed in 1940 and successfully captures the style of the ethnic group depicted. Another simply fantastic and interesting work. The "Air" for Solo Violin and Strings shares much in common with the Hymn and Fuguing Tune and shows just how close the American and English pastoral traditions can sometimes come to each other. The "Old American Counrty Set" was inspired by memories of Cowell's childhood in the Midwest, including his cousin's fiddling, choral-like hymns that often were sung by his relatives, music of merry noise-makers that played and sang outside the houses of newlyweds on their wedding night, and a rapid "cornpipe" rhythm tune that a different cousin sang while husking corn in Iowa. It's all delightful. The "Adagio" (from Cowell's piece "Ensemble") is a dark, unison line of music which runs atonally through a string quintet/orchestra for sixty measures.