Here is one fairly simple way to write a basic walking bass line, courtesy of Steve Skop, the bass teacher for a number of our Wayland students. (There are many ways to add variety, like: varied rhythms to support soloist, ostinato lines, ascending & descending lines in one direction for at least two measures, etc. The formula below is for a basic walking line.)
1) Beat 1 of each measure, write either the root or octave.
2) Beat 4 of each measure, write a chromatic approach to beat 1 of the next measure. (He suggested avoiding using too much of the chromatic from below - too much like the “7 - 1” sound and mostly we want to hear “b7 - 1.” Use it sometimes for color.)
3) Fill in beats 2 & 3. Be careful if you are using the 4th; if it follows the root it can often sound like a dominant-tonic relationship. It's safer to avoid the 4th, especially on beat 2.
A good line looks like:
not like:
Try your own here for this blues in Bb:
Bb7 Eb7 Bb7
Eb7 Bb7
F7 Eb7 Bb7 F7
