Chords played on the bass can be a very effective colour and can offer us more possibilities in small band arrangements, so it might be worthwhile considering some available options for common chords. If we look at three chord types – minor seven, dominant seven, and major seven – then two obvious possibilities for each type present themselves: root, third, and seventh; or root, seventh and third. In fact, you are quite possibly familiar with these particular shapes already as they are commonly used. In the first example I have arranged them as two ways to play a II-V-I chord progression, thus covering the two types of voicing for each chord type. Notice how the third and seventh of the minor seven chord become, with just one note moving a semitone, the seventh and third of the dominant seven chord. Economical voice leading such as this makes for satisfyingly smooth changes between the chords.
But what other options might we have, bearing in mind that root, third, and seventh are usually considered the notes most essential to spell out the harmony? In fact, context is everything, and any of those essential notes may, at times, be omitted yet sufficiently implied given the appropriate context. The second example shows how we might play our three chord types with, perhaps counter-intuitively, the root note on the top of the voicing. The major seven version of this is both a bit of a stretch and also may be rather dissonant for some with the semitone interval, but as a passing chord in the right context it can be useful.
Also in the second example I’ve demonstrated how we might play a II-V pattern, moving between the minor seven chord with the root on the top and, by moving just one semitone, to the dominant seven chord with the fifth on top. This means that in the dominant seven chord there is no root note, though it is sufficiently implied in the context.
So now we have four new chord shapes beyond the six common shapes in the first example – each of our three types with the root on the top and also a dominant seven chord with the fifth on the top. Let’s consider just our two new dominant seven shapes, with the root or fifth on top. We can use these same shapes to represent a dominant seven chord a tritone away, that is, a flattened fifth or three whole tones away. We can think of this as a tritone substitution – for example F#7 for C7, the two chords sharing the same third and seventh – or as the same chord but with a different note on top, so now the dominant seven shape with the root on the top represents a dominant seven with the flattened fifth on top, and the dominant seven with the fifth on top becomes a dominant seven with a flattened ninth on top.
The third example shows how we might combine these voicings along with more common ones to give us four ways of playing a II-V-I in a minor key, in this case using a dominant chord as the II chord. Notice that by combining these different chord shapes we are able to create a line with good voice leading, in this case creating an overall descending pattern finally resolving on a minor triad. But by combining these and other voicings in different ways it would be equally possible to voice lead an ascending line – you only need to learn a relatively small number of new voicings to then be able to combine them in many different ways, creating many more options than you might imagine.
The final example is a blues in F which introduces just one more dominant seven shape which, as with the fifth and root on top, can also be used to represent a dominant chord a flattened fifth away. I have written the chords as half or whole notes, but when you get the shapes under your fingers you can interpret the piece with an appropriate swing feel.
The first bar has the root note on top, which becomes the fifth on the second bar, the IV chord, and back to the root on bar three as we return to the I chord. The fourth bar has the top note raised a tone to become the ninth, this being our new dominant seven shape. This gives us a little variation on the two bars of F7, bars three and four, and also leads nicely to the seventh of the Bb7 chord on the fifth bar.
Again, to avoid repeating the same voicing on the sixth bar, also Bb7, I revert to our dominant seven shape with the fifth on top, which leads nicely to bar seven where we return to the I chord with the root on top, the same resolution as in bars two to three.
On the eighth bar we play a III-VI chord change, A minor 7 to D7, but on the D7 I have used the dominant seven shape which gives us the flattened fifth on top – or you could consider it as an Ab7 – providing a nice descending semitone line leading to the G minor 7 on bar nine with the root on top. Bar 10, a C7, is our new shape again, the same one we used to represent an F7 in bar four, but now it’s a tritone away in relation to the root and thus represents a C7 with an augmented fifth. Again this makes for smooth voice leading as we move to the F7 on bar 11 with the third on top.
The last two bars are a turnaround, I-VI-II-V, and so the second half of bar 11 is a D7 with the augmented fifth on top, creating an ascending line against the harmony, and leading to the third on top on the G minor 7 chord in bar 12, the top note remaining the same for the C7 at the end of bar 12. Using these same voicings it would be possible to play the same progression in many different ways depending on how we combine the chord shapes. This reinforces the point that, as we learn new chord shapes, we exponentially increase the possible combinations, creating many voice leading possibilities. This gives us the ability to play a descending line, an ascending line, or to stay in much the same area even as the chords change, thus ensuring plenty of potential variation in any chordal passages we might be required to play.