A Good Way To Practice Walking Bass Lines
Warning: This is one of those mental exercises which may fry your brain at first. If you feel fatigued, stop and rest, never push yourself beyond what you can comfortably endure.
Do not use a metronome for this exercise, this is a mental exercise and worrying about groove with only distract you.
Pick a range of five frets anywhere on your bass. Within this range you will have all twelve notes of the chromatic scale, plus a few more. This means that within this range you can walk over every possible chord sequence. Let's take this untapped freedom and make a practice exercise out of it.
Take a simple chord progression, for example a 12-bar blues. Those of you more confident with scales might want to pick a relatively simple jazz tune, for example I Got Rhythm. Now write out the chords using roman numerals. I'm going to show what this means by using a 12-bar blues in C as an example.
Chords for a 12-bar in C: |C7|F7|C7|%|F7|%|C7|%|G7|F7|C7|%|
(% = repeat last bar. This is a very common sign found in music notation and chord charts.) When writing out a sequence, your are naming each chord not with a note, but rather by it's relationship with the key of the piece. We are in the key of C, so the C chord becomes the I chord, in this case a I7. F is the fourth of C, so the F7 chord becomes IV7.
Let's look at that progression again, but this time we'll write the chords as roman numerals: |I7|IV7|I7|%|IV7|%|I7|%|V7|IV7|I7|%|
The advantage of thinking about chords in this way is that it becomes easy to transpose them (play them in a different key from the original). Transposing the chords into a different key is essential for this method of practice.
Each "position" is a range of five frets. Begin using frets zero (ie open string) to four. The exercise described below is for one range of five frets. When you have completed it, move your position up by one fret and do it again. Continue this until you have reached the opposite end of the fretboard.
Staying strictly within your 5-fret range, play the arpeggio of each chord. Start with the lowest note of that chord available within your range, and do not stop until you have reached the highest note available, and then return back down. For the C7, our lowest note would be the open E string. The next note would be the G on the third fret of the E string. Next is the Bb on the first fret of the A string, followed by the C on the third fret of the A string. Then the E on fret three of the D string, then the open G string, and finally the Bb on the third fret of the G string. Do this for every chord, always staying strictly within your 5-fret range.
Now it's time to play the whole sequence. The idea is that you walk from the lowest chord tone within your 5-fret range to the highest, exactly as before, but with one difference. This time the chords are moving. This means you have to be always looking ahead four beats so you're ready for the next chord. I'm now going to talk you through the first four chords.
The lowest note is the open E string. Then the G on fret three of the E string. Then the Bb on fret one of the A string, and then the C on fret three of the A string. We have now played four beats, and it's time to change chord.
Continuing to move up within our 5-fret range, the next note of F7 is the Eb on fret one of the D string, Then the F on fret three of the D string. Then the A on fret two of the G string. This is the highest note of F7 within our 5-fret range, so it's time to move down for the fourth beat back to the F on fret three of the D string.
We're back on the C chord, and continuing down within our 5-fret range. The next note is E on the second fret of the D string. Then, C on the third fret of the A string, then Bb of the first fret of the A string, and finally the G on the third fret of the E string.
The C7 chord repeats at this point in the sequence, and the land on the open E string on beat one. This is where we started, so we can follow the same pattern we used on the very first C7 chord. It's not often we get the luxury of repeating ourselves.
Once you have played through the entire chord sequence in this way, it's time for some free walking. Have your metronome click on beats two and four (for that jazzy swing feel), or play along to a jazz drum track, or do whatever you gotta do to get your groove on. Start walking, again staying within your 5-fret range, but this time you can play any note in any order. Don't worry about going up or down, about hitting every note of every chord, just play what sounds good.
Once you've done this, go back to the top and do this whole exercise again, but this time nudge your 5-fret position up by one fret. You'll get at least a good hour's practice out of this one, and here's the final part to remember: Once you have done every arpeggio of every chord in every 5-fret position all the way to the top of the neck, transpose the whole song to the next key on the circle of fifths, and start all over again.
What else do I need to do to master walking bass lines?
Listen to walking bass lines, as many as you can and as often as you can. Listen not only to the notes, but to the feel. Listen to how the bass grooves with the drums, and the rest of the rhythm section. Feel is as big a part of walking bass lines as note choice.
Transcribe walking bass lines. This will get you listening harder, and you will learn about the kinds of note choices different players from different eras make. Learn your scales and modes. This puts your chord arpeggios into context, and gives you many options for passing notes between chord tones, and for other ways you can change the overall harmony through your choice of notes.
There are two books I recommend; Beginning Walking Bass Lines, and Expanding Walking Bass Lines, both by Ed Friedland. Excellent books.
Play lots of walking bass lines, and play them with other live musicians whenever you can. Learn the chords to some popular jazz standards like Autumn Leaves or I Got Rhythm, and go out and play with people.