In country music, walkdown is a bassline which connects two chords whose roots are a third apart, often featuring an inverted chord. See: slash chord. A walkup would be the converse.
For example G and Em (a minor third apart) may be joined by an intervening chord to create stepwise motion in the bass: G-D/F♯-Em (I-V-vi).
In jazz, a walkdown is a descending bassline below chords sharing a common tone. For example, if the above was G-D/F♯-Em7 the bassline would descend, G, F♯, E, while D is held in common.
Walkdown may also refer to the movement from V to IV in bars nine and ten of the twelve-bar blues.
See also 
- ^ Wilson, Steven Robert (1985). On the Importance of Popular Music Theory in the Curriculum, p.62. University of California, Santa Cruz.
- ^ De Mause, Alan (2002). Complete Fingerstyle Jazz Guitar, p.181. ISBN 9780786665594.
- ^ Julin, Don (2012). Mandolin For Dummies, p.174. ISBN 9781119943969.