We do a lot of chord tone accompaniment playing, i.e. follow the chords and play their tones. We fill with scale notes and of course use scale notes when we play melody. But, most of the time we are using chord tones. So.... The following helped me see and find those chord tones on my fretboard.
Bass Patterns based upon the Major Scale box.
Major Scale Box.
Code:
G|---2---|-------|---3---|---4---| 1st string
D|---6---|-------|---7---|---8---|
A|---3---|---4---|-------|---5---|
E|-------|---R---|-------|---2---|4th string
The Cmaj7 chord is coming up in the song. If I place
the R (root note) on the 4th string 8th fret, which is
a C note every thing I need is waiting for me within
the "box".
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 R-3-5-8, three minor R-b3-5-b7 and one diminished chord R-b3-b5-b7, 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 will keep you gigging.
C note at the 4th string, 8th fret, or 3rd string 3rd fret which one should you use? Depends.
The I IV V chord progression has been used in a zillion songs. In the key of C that would be the C, F & G chords. Place the root C on the 3rd string, where are the F & G notes? Yep, right above and below the C. That was a very large WOW for me. Look for D-G-A or G-C-D - yep, piece of cake.
Visualize the box, place the root, what you need is always in the same spot within the box waiting on you.
For example:
Need the 2 - its on the same string as the root and over two frets.
Need the 3 - its up a string and back one fret.
Need the 4 - its up a string same fret.
Need the 5 - its up a string and over two frets. Or just below the R same fret, lower string.
Need the 6 - its up two string and back one fret. Over the 3.
Need the 7 - its up two strings and over one fret.
Need the b3 or any flatted note - move one fret back toward the nut.
IF, big IF, you think in scale degrees this will help. If you are reading standard notation and looking for the note name, C, D, E, F, etc. then this will help;
http://www.studybass.com/lessons/reading-music/bass-clef-fretboard-notes/. and then click on "Bass clef notes on the fretboard" for where those notes are on your fretboard. Notice our fretboard has three octaves, I think of it as being lower ledger notes, staff notes and upper ledger notes - that's my way of keeping the three octaves in place.
I did not mention tabs. Tabs are OK for working out specific phrases, but, I do not recommend them as a way of playing complete songs.
Have fun.