And while bass is easier to begin learning to play than a regular guitar, it's not a simple instrument. Yeah, getting a nice low end rumble in a song is great, but that is far from the only contribution a bassist makes to the band as a whole. The role of a bassist breaks down easily into two broad categories: establishing the rhythmic foundation, and providing the harmonic foundation.
Establishing the Rhythmic FoundationThis is the pulse of the music, helping the drummer to flavor the beat and keep everyone's feet tapping along. Though it's easy for us to expect this from the drummer, a good bassist ensures that the rest of the band is playing at a consistent tempo throughout each song.
Providing the Harmonic FoundationOf course other instruments, such as pianos and guitars, often play chords made up of multiple notes in harmony with one another. When we hear several notes being played at the same time, we hear them relative to the lowest note. This means that whatever the bass guitar is playing in conjunction with these other instruments will help define the overall mood the song or section is trying to convey to the listener.
When constructing bass lines, one of the most commonly used patterns is "roots and fifths." The combination of root notes and fifth notes is often pleasant to the ear and can work for nearly every application. Even though it's a very simple concept, when used effectively it can keep the rhythm moving steadily and reinforce the core of the song's chord progression.
Root NotesA root note is the foundation of a chord, the note on which the chord is built. Most of the time it is the note for which the chord is named, so when you hear someone shout out the chord progression, you can use that as you root map. As we already covered, the role of the bassist is to define the chord with a steady rhythm. Playing the root note is a simple way to ground the foundation of the chord.
When playing root notes, you don't have to restrain yourself to just the 4th string. You can play an octave of the root note (or any note) easily by moving 2 strings over and 2 frets up. For example, the G note can be found on the 3rd fret of the E string, and also on the 5th fret of the D string. Likewise, you can play the E note as an open note on the E string, or on the 2nd fret of the D string.
Root notes get a lot of hate sometimes, because when used exclusively the bass line can get pretty boring. But it really just depends on what the song calls for. They are a great practice tool when jamming with friends to help you get to know your fret board.
FifthsTwo of the notes which form a chord are the root note and the fifth note. The bass can play these notes to extenuate the chord. I won't go into all the details, but it is called a fifth note because it is the 5th note in the scale from which it comes. (You can find plenty of lessons on understanding scales that will help you more than a quick explanation in this lesson. Those of you who have played power chords on a guitar know this concept very well, even if you don't realize it.
The fifth note above the root is always on the next highest string, and two frets up. The fifth above the root note 2 on the A string (the note B) is 4 on the D string (the note F#). The fifth below any note is just an octave of the fifth above, and can be found on the next lower string and on the same fret. So the fifth below fret 2 on the A string is fret 2 on the E string.
You can see the root and fifth pattern being used in lots of songs. Here are some examples:
The well known bass riff in "Billy Jean" by Michael Jackson
and the introduction to "My Girl" by the Temptations
I hope that this lesson was helpful to you as a bassist, and that you will be able to use these concepts when crafting your own bass lines.