The music was a social medium at first, that gathered people and make them dance together. Before Jazz and dance balls, there were square dances, documented as early as the 16th century in England, in France and throughout Europe. These dances came to North America with the settlers and have been considerably developped there since. Nowadays, “square dances” are associated with Western America and the romantized image of the cowboys.
The dance figures are not improvised but set in order and repeated by a caller. Caller that can on his side improvise the order of the figures. You can hear the calls over the music on the following records. Records that had the purpose of offering “old time” dance music with calls, so that you could dance at home just like if you were at the barn parties…or listening to the WLS National Barn Dance program. 
The Tom Owen’s Barn Dance Trio was led by Tom Owen, a National Barn Dance resident, square dance caller, native from Missourri, accompanied by a guitarist left unknown and a fiddler that could be Tommy Dandurand according to Tony Russel and most historians ; but the absence of data, and comparisons of recording transcriptions forbid to jump to that conclusion . That fiddler will probably left unknown forever as well.
The trio recorded 8 sides in Gennett’s studio, in Richmond, Indiana on february 1926. They were released on Gennett and also spread through most of the label’s client labels and subsidiaries, like the Silvertone here. The band appears as “Uncle John Harvey’s Old Time Dance Orchestra” on Herwin.
Tommy Dandurand, born in 1865 in Illinois, third generation of french settlers, appeared regularly on the National Barn Dance from autumn 1924 throughout the 30’s. Even though there is no evidence to confirm this claim, he is considered as the first fiddler to appear on the NBD . There seems to be quite some holes in the program history, and Dandurand seems to pay for it: he definitively is an important old-time fiddler, and NBD artist, but many details are still unclear on the role he played at the beginning of the show.
In 1927, he made two trips to the Gennett studio in Chicago, where he recorded 14 sides with his Barn Dance Gang from wich 13 have square dance calls, all by Ed Goudreau.
The Hill Billies, appearing as “Al Hopkins & his Buckle Busters” on Brunswick, were not a NBD artist, but released this record in the tradition of square dance music with calls, wich diserves to appear here..
The WLS NBD did not offer only string bands with calls. There were also numerous of artists playing folk/country songs, in bands or alone. Among them, there was Luther Ossenbrink, as Arkie the Arkansas Woodchopper, that I have talk about here.
There was also Walter Peterson playing guitar and harmonica. Little is known about the man himself, but he was regularly scheduled from as early as the second week of the show throughout 1929, sometimes announced as The Kentucky Wonder Bean !
Peterson recorded for Paramount in spring of 1924, but only two sides. The core of his discography has been recorded for Gennett throughout 1927. He appears sometimes under the pseudonyms “Jess Jenkins” or “Abner Burkhardt”.
There was also Bradley Kincaid, folksinger and one of the first radio stars of the US. He joined the NBD as part of the YMCA Quartet in 1926, for a weekday show. Don Malin, WLS’ music director, invited him on the saturday night show to sing some old tunes, aware of Kincaid’s large repertoire of folksongs. His initial goal was formal music education, but the paycheck and hundred of appreciative letters from listeners convinced him to give radio a try . He appeared as a favorite of the NBD during the next four years, until he left WLS for WLW in Cincinnatti. And as the show liked nicknames, his was called The Kentucky Mountain Boy.
From 1927 to late 1929, he intensively recorded for Gennett, and appeared sometimes as “Dan Hughey” on Champion. The subcredit “WLS artist” appears on all Sears & Roebuck Co. labels.
The following images are taken from Cowboy Dances – A collection of Western square dances (Lloyd Shaw, 1939), scans courtesy of traditionalmusic.co.uk
 The National Barn Dance was one of the longest running radio show, starting in 1924 on station WLS until 1960, aired on saturday night on a weekly basis. It is the direct precursor of the Grand Ole Opry.
The Sears, Roebuck and Company (unformally known as Sears) is an American chain of department stores founded in 1893. In the early 20’s, it was a major retail and mailorder company. To get farmers and mid-west people to buy radio sets from their catalog, Sears bought time on radio stations, and soon decieded to start its own station. WLS (for “World’s Largest Store”) started officially in early april 1924. Later that month, WLS aired its first National Barn Dance show on a saturday night, wich was one of the very first country music programs.
During the 20’s, radio was a strong competitor to the record companies. Sears saw an opportunity to win on both sides and entered into a five years agreement with Gennett to record WLS artists and produce budget labels featuring them (Silvertone, Challenge, Supertone or Conqueror) beside its own lines of labels.
For more details and abundant iconography about WLS and the National Barn Dance, I recommand wlshistory.com
 Country Music Records, a discography, 1921-1942 (Tony Russel, Oxford University Press, 2004) p.672
 The Hayloft Gang: The Story of the National Barn Dance (Chad Berry, University of Illinois Press, 2008) p.43,44
 Ibid. p.43
 Ibid. p.47