Watch the Day 22 online guitar lesson by Chris Buono from 40 Day Rhythm SWAT Camp

In 1937 a young Oklahoma guitarist named Eldon Shamblin joined Bob Wills & His Texas Playboys. For Shamblin, performing with this legendary Western swing outfit was a dream come true. Shamblin was self-taught, and his rhythm style was highly influenced by the big band music of the time. His early guitar work with the Playboys was solid and swinging, but in 1940, when Wills requested that Shamblin include a lot of bass runs in his guitar part during the recording session for "Take Me Back to Tulsa," Shamblin responded with a unique two-beat traveling-bass rhythm arrangement. This approach not only became his trademark sound and cemented his reputation in history as one of the greatest rhythm guitarists ever, it forever defined the Western swing guitar style.

Although playing open-string bass runs was not unusual for dance band guitarists of the time, Shamblin used his knowledge of jazz and large-ensemble arranging to harmonize his bass lines with a series of mostly closevoiced chord forms. The example below is a typical Shamblin-style arrangement that can be used on a "San Antonio Rose"-type (I-IV-II-V-I) progression.

In measures 1 and 2, we see how Sheldon creates a descending bass line starting with a D chord, moving through two inversions of D7 (D/C and D7/A). At measure 3, alternating bass is used on the G barre chord. Descending to the 7, D, of E7 (E7/D) sets us up nicely for a half-step bass drop into A9/C #. Measure 5 features a slick maneuver where Em/B shifts smoothly into the A dominant harmonies in the next bar, which resolve, finally, back to D major in bar 7. On the second pass, we see a variation used: Measures 9-11 start with a first-inversion D chord and descend down to bar 11's G/B, using bar 9's Am/E as a passing chord.