Inversions can be a real fun way of using the fourth and fifth elements of the bass line hierarchy (from my column back in November). If you look in the Harvard Dictionary of Music, the definition of an inversion takes up half a page. I’m going to define it in a way that is simpler and more useful for us bassist: an inversion is when you treat another part of the chord as if it were the root.
This can be done in a number of ways. The simplest way is to only play that notes against the corresponding chord. Another thing is to make that sure that note is on the downbeat of the measure, or to make it the lowest pitch you play. Put both of those together and it makes the inverting much clearer. You could also play it more than the other notes in the measure. As you experiment, you may even come up with some other methods.
So let’s come up with some examples. I’m going to use a brilliant chord progression that was written by almost every guitarist you’ve ever worked with: D C G D. So what are some options for inversions? Well, if we’re just using triads, and only invert the first chord (which makes it sound like a change from the final chord, instantly providing this chord sequence with some forward impetus) we have D/F# C G D, or D/A C G D. If we wanted to get a little farther out, we could put the seventh under the first chord, providing us with D/C C G D. This is an intriguing sound, as the bass note stays the same for the first two chords, with the chord changing, but from the end to the beginning the chord is the same but the bass note changes.
So let’s take the first one and come up with some ideas on how we can create bass lines around it.
We could play whole notes or straight eighths on the low notes, but let’s see what else we can do. I came up with four different lines for this chord progression. For example one I leaned on the first note, and then just played a line through the related scale (D Mixolydian in this case) to get to the next one. For the first three chords two scale tones always worked (though I had to jump up an octave on the G chord to keep the line in four-string range) and for the final D I just jumped to the fifth to drop two notes back to the beginning.
For the second example, I created a more driving line by using an almost steady stream of eight notes. I also implied a counterpoint by using two pitches in each measure, but while the bottom goes through the chord progressions “roots” (F#, C, G, D), the high part ascends through the scale (F#, G, G, A). Notice how each of these notes are still part of the underlying chord.
Example number 3 has a more latinish rhythm, and most of the notes fit in with the chord. The exceptions are where the final note of the measure is used to lead to the next measure, in measure 1 it’s the fifth of the next chord and in measure 3 it’s the third. Notice how in the first measure F# is the first note but not the lowest. The line drops down to the root, but it still creates the sound of an inversion.
For example 4 I didn’t play the downbeat at all, giving it a reggae vibe (though if it’s slapped, it sounds really badass). Even though the chord progression is supposed to be D/F# C G D, the treatment of the chords in this bassline makes it unclear which chords are inverted. The G almost sounds like G/B, and both the C and the last D, though they have the root note as the lowest note, it’s between two other accented notes, making both almost sound like they could be inverted.
Now come up with some of your own. Also, discover how it sounds when you invert other parts of this chord progression, e.g. D C/G G D, or D C/G, G/B, D, or D/C C/E G/D D.
You can hear me play the examples here.