Although my initial desire to be a bassist was sparked by Paul McCartney’s playing on the Beatles' classics, I essentially learned to play by emulating the playing of a certain progressive rock bassist who is famous for a riff-oriented, generally "busy" style of playing. Consequently, my playing for years was characterized by a lot of guitar-like, unrelated and random (albeit harmonically & technically correct) snippets. While certain musical settings may lend themselves to this constant variation in the bass line (usually by arranging the other instruments around the bass), the overwhelming majority of the music most of us find ourselves playing calls for a different musical approach.

PLAY A PART

My older brother and musical mentor in the early years used to talk to me about establishing a motif, or employing a theme and variation approach in my bass playing. It took me many years before I truly understood the importance of this concept.

It boils down to how people hear music.

Let me illustrate - compare these two examples:

Audio Example 1

Audio Example 2

 
 

The difference between these examples is that Example 1 involves constant variation and no discernible recurring figure, while Example 2 employs a motif.

The idea behind playing thematically is that most effective bass lines (and most effective music, in general) involve a specific figure, or motif, that is somewhat repetitive (establishing a foundation for the tune, as well as giving the listener something to grasp and your drummer a consistent rhythmic figure with which to play), and that incorporates variations progressively as the tune develops.

Here’s a simple bass and drum groove that uses a repetitive motif:

Audio Example 3

 
 

A motif in the bass line can give solidity even if the drummer is incorporating frequent variations. Listen to how the bass motif holds things together in the following clip.

Audio Example 4

 
 

Let’s contrast that: here’s the same drum part, but now the bass will begin to deviate from the rhythmic motif after the first few passes...

Audio Example 5

 
 

Again, context is everything; there may be certain rock settings where the randomness of Example 5 might still work...but in terms of general musical application, it probably wouldn’t support an ensemble as well as the motif approach of Example 4.

The motif doesn’t necessarily need to be overly simple. Here’s an example of a motif that is a bit more involved:

Audio Example 6

 
 

I encourage you to analytically listen to some of your favorite music and try to identify the use of motifs (by the bass as well as the other instruments), and a general thematic approach. I'm confident that you'll find numerous examples.

I feel that application of this concept to my bass playing was one of the most important factors in my own musical development.