My old standby chart of generic bass lines using the major scale box as a Rosetta stone.
Major Scale Box.
G|---2---|-------|---3---|---4---| 1st string
D|---6---|-------|---7---|---8---|
A|---3---|---4---|-------|---5---|
E|-------|---R---|-------|---2---|4th string
Cmaj7 chord coming up in the song. Find a C note on the 3rd or 4th string. Put the box's R over that C and then play the spelling for a Cmaj7 chord. That is the R-3-5-7 scale degrees found within the box. Here is the rest of the story.....
Basic Chords
• Major Triad = R-3-5
• Minor Triad = R-b3-5
• Diminished Chord = R-b3-b5
7th Chords
• Maj7 = R-3-5-7
• Minor 7 = R-b3-5-b7
• Dominant 7 = R-3-5-b7
• ½ diminished = R-b3-b5-b7
• Full diminished = R-b3-b5-bb7
See a chord and play it's chord tones. As every key will have three major, three minor and one diminished chord it's a good idea to get your major, minor and diminished bass line chord tones into muscle memory so when you see a chord your fingers just know what will work. Now the song may only give you enough room for the root, or root five - adapt and get as many chord tones into your bass line as needed. Root on 1 and a steady groove from the other chord tones plus something to call attention to the chord change is what we do. Ed Friedland's book Building Walking Bass Lines will help with calling attention to the next chord change.
Scales - Yep gotta do our scales so our fingers know where the notes are and our ears recognize the good notes from the bad notes.
• Major Scale = R-2-3-4-5-6-7 Home base
• Major Pentatonic = R-2-3-5-6 Leave out the 4 & 7
• Natural Minor Scale = R-2-b3-4-5-b6-b7 Major scale with the 3, 6 & 7 flatted.
• Minor Pentatonic = R-b3-4-5-b7 Leave out the 2 & 6.
• Blues = R-b3-4-b5-5-b7 Minor pentatonic with the blue note b5 added.
• Harmonic Minor Scale = R-2-b3-4-5-b6-7 Natural minor with a natural 7.
• Melodic Minor Scale = R-2-b3-4-5-6-7 Major scale with a b3.
Let the major scale be your home base then change a few notes and you have something different. No need to memorize a zillion patterns. Let the major scale pattern be your go to pattern - then adapt/adjust from there. You probably only will need the Major and natural minor scale, however, to keep it from being boring I've given you some of the other scales you might want to get under your fingers.
But, 90% of what we do is play chord tones not scales so the following needs to get into muscle memory.
Generic Notes - for your bass line.
• The root, five and eight are generic and fit most any chord. Remember the diminished has a flatted 5.
• The 3 is generic to all major chords. So R-3-5-3 will fit under any major chord.
• The b3 is generic to all minor chords. And R-b3-5-8 will fit under any minor chord. Why the 8? Well the 8 is just another root in the next octave.
• The 7 is generic to all maj7 chords. Yep, R-3-5-7 fits nicely.
• The b7 is generic to all dominant seventh and minor seventh chords. G7 = R-3-5-b7 or Gm7 = R-b3-5-b7.
• The 6 is neutral and adds color, help yourself to 6’s. Love the sound of R-3-5-6 with a major chord.
• The 2 and 4 make good passing notes. Don’t linger on them or stop on them, keep them passing.
• In making your bass line help yourself to those notes, just use them correctly.
• Roots, fives, eights and the correct 3 & 7 will play a lot of bass.
