Ideas for this progression

[Phantasm]

My guitarist likes to play progressions similar to these, and I'm looking for new melodic ideas of what to play as a bassist over this sort of thing. Specifically, ideas of scales or modes that will work over this would be great. My theory is average at best, so i don't know the "technical name" of what he's doing here.

 

G--5- -4- -1- -2- -9-

D--7- -5- -2- -2- -9-

A--0- -0- -0- -0- -7-

 

Thanks to all who offer advice.

[Poparad]

This is a good example of guitar chord voicings that don't use the root of the chord as the bottom note of the voicing. Usually as a bass player, your job is to play the roots of chords, and you can usually rely on just playing the bottom note of the guitarist's chords. However, when you get some chords that are inverted (the root not being on the bottom), then you have to hunt a little for your notes.


The very simplest thing you could do is to just copy the pedal point of the chords here. A pedal point refers to when the bass note stays the same, but the chords on top change. The effect created is a solid, constant bottom but with shifting sounds in relation. Granted, this is incredibly boring to do as a bassist, but you can use this in addition to moving around for contrast.

Now comes the tricky part: figuring out what the actual roots of the chords are. With the exception of the third chord, these can all be figured out easily.

Take the notes of each chord, and rearrange them so that they're spelled out as normal triads. Then it might become more apparent what the roots are.


The first chord's notes are A, A, and C. To me, this is an A minor chord (A C E). When you just have 2 notes a third apart like this, you can consider the lower note the root. Basically, this is just a normal triad, but the E on top has been omitted, so you're left with just A and C. The doubled A is also a big hint towards A being the root.

The next chord has the notes (bottom to top) A D and F#. If you rearrange these so they're all thirds apart, it becomes D F# A, or D major. D is the root in this case.


Now for the third chord... a little tricky here. This isn't just a basic triad... it's actually implying a 4 note chord. In this case, I would say it's Amaj7 (A C# E G#). In this case, the third (C#) has been dropped. This is somewhat unusual to see the third dropped, but it does happen.

The next chord is just an A5 (A E). This could be Amajor, it could be A minor. Since we've seen both an A minor chord already, and since the previous chord didn't have the third to make it major or minor, it's kind of up in the air whether this is Amajor or Aminor. Nonetheless, A is still the root.

The last chord is just an E5 (E B). Once again, could be major, could be minor. I would lean towards E major, but it's ambiguous and could very well be E minor. Once again, E is still the root either way.


Now, as a bassist, even though you usually just play roots, you don't have to all the time. You could create your own inversions by playing the third or the fifth of chords. Sometimes this can help create really nice, connected lines instead of jumping around from root to root.


With this progression, you could play this: A, D, C#, C, B E.
That would be the root of the first chord (A), the root of the second chord (D), the third of the third chord (C#), the third of the fourth chord ©, and then you could play both B (5th) and then to E (root) on the last chord.

[Phantasm]

Good stuff. Thanks!

Edit: Whoops, except that I just noticed that the 2nd chord is A G B, not A D F#. But by your same logic the chord center would be G.