The function of the bass in a traditional rhythm section is somewhat different than that of a chordal instrument. Like a pianist, a bassist must normally outline the chord changes, but the bass usually emphasizes the roots, thirds, and fifths rather than any extensions or alterations. In traditional jazz forms, the bass player also has a very important role as a timekeeper; as much as a drummer, if not more so. That is why bass players so often play walking bass lines that consist almost exclusively of quarter notes or rhythms that strongly emphasize the beat.
In this respect, learning to play bass lines is often easier than learning to solo or play voicings. You do not have to worry much about what rhythms to play, and your note choices are more limited as well. When you listen to great bass players like Ray Brown or Paul Chambers, you will see that a large part of their playing is quarter notes and scale based lines.
When a pianist plays in a solo setting, he must often provide his own bass line accompaniment, so pianists should learn how to construct good bass lines as well.
There are some simple guidelines you can use to produce good sounding bass lines. First, you generally should play the root of the chord on the first beat of that chord. The previous beat should be a note a step away. For instance, if the chord F7 appears on beat “one” of a measure, then you would normally play F on that beat. You would normally play E, Eb, G, or Gb on the last beat of the previous measure, depending on the chord. If the chord was C7, then you might play either E or G, since they are in the associated mixolydian scale. Or, you might think HW diminished or altered scale for the C7 and play the Eb or Gb. The Gb is also the root of the dominant chord a tritone away, which has already been described as a good substitution, so Gb makes a particularly good choice. The note does not necessarily have to be justifiable in the context of the chord; it can be thought of as a passing tone to reach the first beat (the downbeat) of the next measure.
These first two guidelines take care of two beats for each chord. In some tunes, such as any song based on the rhythm changes, that is all you get for most chords, so your bass line can be almost completely determined by the chord progression. Of course, you will probably want to vary your lines. You are not required to play the root on the one, nor are you required to approach it by step. Remember, these are only guidelines to get you started.
If you have more than two beats to fill for a particular chord, one way to fill the remaining beats is to simply choose notes from any associated scale in mostly stepwise motion. For instance, if your chord progression is C7 to F7, and you have already decided to play “C, x, x, Gb” for the C7 chord, then you can fill in the x’s with D and E, implying the lydian dominant scale, or Bb and Ab, implying the altered scale. Either of these choices might also imply the whole tone scale. Another popular pattern would be “C, D, Eb, E”, where the Eb is used as passing tone between the D and the E. You will probably discover other patterns that you will tend to use a lot. Playing patterns is generally frowned upon when soloing, where you are expected to be as creative as possible. When accompanying, however, patterns, like those given for voicings, can be an effective way to outline the harmony consistently. As a bass player, you are expected to play virtually every beat of every measure for the entire piece. It is usually more important to be solid and dependable than to be as inventive as possible.
The term pedal point, often shortened to simply pedal, refers to a bass line that stays on one note over a changing harmony. Certain songs, such as John Coltrane’s “Naima”, from the album “Giant Steps”, are written with explicit pedal point, either with the notation “Eb pedal” over the first four measures, or through the notation of the chords as
| Dbma7/Eb | Ebm7 | Amaj7#11/Eb Gmaj7#11/Eb | Abmaj7/Eb |.
When you see a song explicitly call for pedal point, that is usually an indication to stop walking and instead play only whole notes.
You can also find your own opportunities to use pedal point. In a ii-V-I progression, the fifth can often be used as a pedal note. For example, you can play G under the progression | Dm7 | G7 | Cmaj7 |, or just under the first two bars. Under the Dm7 chord, the G in the bass makes the chord function as a G7sus chord. The resolution to the G7 chord then mimics the traditional classical use of suspensions, which always resolve in this manner. This is also commonly done in progressions that alternate between the ii and the V, as in | Dm7 | G7 | Dm7 | G7 | Dm7 | G7 | Dm7 | G7 |.
Scott LaFaro started a small revolution in jazz bass playing in the early 1960’s through his use of counterpoint. His bass lines had almost as much rhythmic and melodic interest as the melody or solo he was accompanying. This can be distracting to some soloists, and to some audiences, but many find the effect exciting.
One opportunity to use counterpoint is in ballads or medium tempo swing tunes where the melody has long notes or rests. One of the most famous examples of Scott LaFaro’s counterpoint is on the version of “Solar” recorded by Bill Evans, Scott LaFaro, and Paul Motian on the album Sunday At The Village Vanguard. The melody is mostly quarter notes, with whole notes at the end of each phrase. Scott plays long notes while the melody is moving, and moving parts where the melody is staying still.
Bob Hurst has a different approach to counterpoint. Rather than playing lines that sustain their own melodic or rhythmic interest, he plays lines that create rhythmic tension in their interaction with the beat. One technique he uses often is playing six notes against four beats, or two quarter note triplets per measure. It sounds like he is playing in three while the rest of the band is in four. This type of rhythmic counterpoint is difficult to sustain for any length of time, and may confuse inexperienced musicians.
When experimenting with counterpoint, remember your role is usually still that of an accompanist. Your goal is to support the musicians you are accompanying. If they are being thrown off by the resultant complexity, or are producing enough rhythmic tension on their own, then this may not be a good technique to use. You will have to use your own judgement to decide when the music will benefit from the use of counterpoint.
The techniques described above are applicable to most styles of jazz. Some particular styles impose their own particular requirements on the bassist, however. A two-beat or half-time feel means playing only on beats one and three in 4/4 time. A two-beat feel is often used on the head for standards. When playing in 3/4 time, you may either play walking lines or just play on the first beat of each measure. Many of the Latin Jazz styles use a simple pattern usually based on alternating roots and fifths. The bossa nova, a Brazilian derived style, uses the root on “one” and the fifth on “three”, with an eighth note pickup on the “and-of-two” and either another pickup on the “and-of-four” or a quarter note on “four”. The samba, another Brazilian derived style, is similar, but is played with a double-time feel, meaning it sounds as if the basic beat is twice as fast as it really is. The root is played on “one” and “three” while the fifth is played on “two” and “four”, with a sixteenth note pickup before each beat. The mambo and other Cuban derived styles use the rhythm “and-of-two, four”. The latter beat is tied over to the “one” of the following measure.
A full description of all the different styles is beyond the scope of this primer. There are a few books that can help you in constructing patterns for various styles; one such book is Essential Styles For The Drummer And Bassist. For now, all I can do is repeat Clark Terry’s advice, “imitate, assimilate, innovate”. Listen to as many different styles as you can and learn from what you hear.