[3] Since 1933, through many changes in membership, the Sons of the Pioneers have remained one of the longest-surviving country music vocal groups.
[5] In September 1931, Canadian-born Bob Nolan answered a classified ad in the Los Angeles Herald-Examiner that read, "Yodeler for old-time act, to travel.
[4] In the spring of 1932, Slye, Spencer, and another singer, Slumber Nichols, left the Rocky Mountaineers to form a trio, which soon failed.
Slye joined Jack LeFevre and His Texas Outlaws, who were a popular act on a local Los Angeles radio station.
[4] By the summer of 1934, the Sons of the Pioneers' popularity and fame extended beyond the Los Angeles area and quickly spread across the United States through short syndicated radio segments that were rebroadcast all over the country.
[4] One of the first songs recorded by the Sons of the Pioneers during that first August session was written by Bob Nolan, "Tumbling Tumbleweeds", that would soon become a staple in their repertoire.
Leonard Slye was rechristened Roy Rogers, and went on to achieve major success as a singing cowboy in the movies.
Agents, music publishers, and recording companies insisted that co-operative bands needed a name to promote them (as in Glen Gray and the Casa Loma Orchestra).
The group, as "Bob Nolan and the Sons of the Pioneers," made guest appearances in the Warner Bros. all-star revue Hollywood Canteen (1944, singing "Tumbling Tumbleweeds") and the RKO Hollywood-themed comedy Ding Dong Williams (1945, singing "Cool Water").
These were syndicated by Standard Transcriptions (1934–36), Mutual (1939, as The Sunshine Ranch), RCA (1940, as Symphonies of the Sage), the Armed Forces Radio Service (1942–45, as Melody Roundup), and Teleways (1947–49, as The Sons of the Pioneers Show).
The group prepared a demonstration record for radio stations and their potential local sponsors, with announcer Art Gilmore reading promotional copy between songs.
The informal, semi-scripted show had Bob Nolan acting as master of ceremonies, bantering with the other singers between numbers.
The group was careful to program a variety of choral music, including cowboy songs, barbershop harmony, sentimental ballads, and spirituals, to appeal to the widest possible audience.
Toward the end of the run, as an economic measure saving both time and money, the later Teleways shows were patched together from previous programs (including some songs with Ditmars), with new spoken dialogue by Nolan and the gang connecting the older performances.
Republic Pictures president Herbert Yates released the Sons of the Pioneers from their movie contract in 1948, replacing them with a less expensive alternative, Foy Willing's Riders of the Purple Sage.
The group continued to record new albums for RCA through the 1960s, the last being a collection of Hawaiian songs, The Sons of the Pioneers Visit the South Seas (1969).
In 1977, the Smithsonian Institution, which designates certain artists and performers who have made a noteworthy contribution to the arts and culture of America, named the Sons of the Pioneers as "National Treasures".
Later notable appearances include: The Sons of the Pioneers were the first Country and Western group to sing at Carnegie Hall, and the first to perform at the lavish nightclubs in Las Vegas.