Many people have requested to learn from me how to play walking bass lines (Jazz Piano).
As a jazz pianist, I find it very useful to know how to play walking bass lines for several reasons. The main reason is that you actually need to understand how the bass works in a band setting in order to play good walking bass lines yourself. 

This is my video from YouTube on how to play walking bass lines (jazz piano):

How to play Walking Bass Lines (Jazz Piano). 

The usage of playing walking bass lines for jazz pianists are many.
For example: You are playing with a singer without a bass player, you’re playing solo jazz piano and want to play accompaniment for yourself while you play your melodies/solos, or you’re playing in a jazz band and the bass player is not showing up! Trust me, this happens all the time

How the bass works

– Normally the bass player plays the root of each chord. That is his job! However, more experimental bass players doesn’t always do this, and we as piano players should never get in the bass players way.

– In swing tunes, the bass players are mixing between playing on 1 and 3, walking bass (on 1,2,3 and 4), as well as playing fills and being a rhythmical support.

– The range of the 4 string double-bass is usually E1 to G4. A good supportive bass player usually plays at the lower part of his instrument.

1. The bass player plays on 1 and 3:

(The bass is sounding an octave lower than it is written)

Also: If you’d draw a line between the notes, you’ll see the typical pattern: A little up, a little down, or the other way around.

2. The bass player walks:

Now you can see that the bass player walks on 1,2,3 and 4.
At the start he plays quite bright (1). This sounds great, but it would probably not sound that good unless he creates a contrast by playing some deeper notes (2).

So we as piano players should keep this in mind! If we just play the same lines over and over, there won’t be any contrast and then you’ll have less friction. If you vary too much when you play the bass lines, you won’t establish a good foundation that you can use to create the important contrast.

Your job when you’ll play your bass lines is to connect the chords.
A key of thumb is to play the root of the chord at the first beat in a bar

Then play notes on each beat, where your goal is to aim for the root of the next chord.

When you play over a I chord, use the diatonic scale starting from the root. (In the example above, you can play notes from the Eb scale).

TIP 2: Add extra notes when it is not adding up.

In this example, there is a II-V-I progression. Bbmi7 – Eb7 – Abmaj7. (The I chord is not included in the image)

At the Bbmi7, you can then start at the root of the chord (Bb). To connect with the next chord (the Eb), the notes won’t add up if you just follow the related scale (the Ab scale in this case).

We can fill this space by adding an extra note. There are several ways to do this. In this example, we added a D before the Eb (1) and in the next example (2) we added Gb before the G (again, the next/last chord would be an Ab).

I’m a big believer in simplifying the complexity of music theory.

For many years I used to work on the modes (Ioinian, dorian, phrygian etc). Then I found out that there is a much simpler way to think: Major scales! That’s what they all are. This principle is also something I use for improvising as well as playing chords.
(This is material for another future lesson, but I cover it all in the Jazz Piano Step-by-Step Course).

The scales:

a) When you play a major 7 chord, use the major scale starting from the root.

b) When you play a minor 7 chord, use the major scale starting down a whole-step. For example: The chord is a Cmi7, you can play the Bb major scale.

c) When you play a dominant 7 chord, use the major scale starting from a 4th above the root of the chord. For example: If the chord is a C7: Play the F major scale.

Occasionally there are chords where this rule won’t apply. For example, when there is a minor 7 with a flat 5 chord. The solution in this case is to play the major scale starting a half step above the root.

I believe this is a lot easier to remember than to try to remember dorian scales and mixolydian scales in all 12 keys. (You just saved yourself of learning 24 additional scales to the diatonic scale you probably already know)

Here is an example:

Check list:

1. Did we play the major scale from a whole step under all of the minor 7 chords?
2. Did we play the major scale from a 4th above all of the dominant 7 chords?
3. Did we play the major scale starting at the root of the maj7-chords?
4. (And we also played the major scale starting from a half-step above the root when we got a minor 7(b5) chord?)
5. Did we fill in extra notes to make it add up? (One note per beat, and still reaching/playing the root of the next chord at the first beat)

When we’re playing bass lines on more than one chord in a bar, you don’t have the time to walk all the way from one chord to the next.

The solution is to add 4 tricks.

You can do this by adding:

• 1/4:  A half step above the next chord
• 2/4: A half step under the next chord
• 3/4: A whole step under the next chord (Not to be used on a V-chord to I-chord)
• 4/4: A whole step above the next chord

Here is an example where we use two of the four types:

This one is easy to explain, but hard to do. When I play syncopated chords while I’m also playing walking bass lines, I simply don’t think. In stead, I try to make it swing. So the question you should ask yourself is not how you should play the syncopations, but how you can make it swing. Then try to play the chords off- beat.

Here is an example from the demo I did on the YouTube video: