Bass line bars not starting on root (iReal b and "All Of Me" content)

[warnergt]

Background
A question came up here on TB about "All Of Me." Out of
curiosity, I checked it out on the iReal B app (available for iPads
and Macs). My chord chart was a little different than what was
presented here but no matter; that is not what I'm looking at.

iReal b is a cool app that generates backing tracks from chord
charts. It creates drums, piano and bass lines. The bass
lines sound amazingly good. So, I decided to take a look at
how it creates a bass line and try to understand it.

I just discovered today that the iReal b app on the Mac can
output to a MIDI file. This made the analysis extra easy as
I could take the MIDI file and see exactly what notes were
generated.

So, I started looking at each bar. It wasn't rocket science but
it was a nice mix-up of note patterns and note durations.
If I heard this live, I would consider the player to be pretty
accomplished. I sure wish I could do this on the fly;
someday perhaps.

Anyway, everything is fine until it gets to the G7 in the last
line of the chord chart. It is bar 31 on the score (the score
starts with bar #2 so score bar #31 is chord chart bar #30).

iReal b chord chart


iReal b bass line for bar in question


Question
The G7 bar is starting with a B. This is something I wouldn't
think to do (especially in a 3-piece band). I would pretty
much without exception always start on the root (G). Oddly,
it sounds pretty good in iReal b. Is that because they have
a piano simultaneously playing the chord? What are your
thoughts on starting bars on non-root notes? Are there some
guidelines or recommendations for this? Or am I
over-analyzing this?

[FretlessMainly]

I wouldn't say that you are over-analyzing things; sometimes it takes a serious questioning of things to find "new" ways of expressing yourself. When I played double bass in a jazz trio I often used non-root notes (but usually other chord tones) on the strong beats (1 and 3 when in 4/4). It's not as uncommon as you think; there are many examples in jazz and in rock (think Plush by STP).

One of the reasons it works well in your example is that there is chromatic (half-step) movement from the b7 of the Dmin7 to the 3rd of G7. Half-step movement is a strong resolution assuming it's executed using the proper half steps!

[Ed Fuqua]

Seen this?

[redname]

i don't see why not as B is a chord tone of G7 (major 3rd) and as far as my teacher and the books been teaching me, a tone chord should be played on the chord changes which can be G, B, D or F in this case

[warnergt]

Originally Posted by Ed Fuqua

Seen this?

I hadn't seen that. That's good!

[Jazzkuma]

As far as walking you can land on 1-3-5-7 of the chord and it will sound "good".

You also have to know about the voice leading and how the ii-V's resolve. But that comes with time once you have more knowledge of jazz theory and when you can feel comfortable playing different chord tones without thinking about it.

You could even play a pedal on G throughout that whole ii-V-I section and it will sound "good".

Listen to Ron Carter for this stuff, theoretically you could spend the whole tune walking without ever hitting a single root chord.

[Ed Fuqua]

If you're just starting out with this music, I'd also like to recommend this, many folks have had nice things to say about it...

[Turxile]

What did you use to convert MIDI to notation & tab, if you don't mind me asking?
The format looks very neat.

[CnB77]

I'd not heard of this program before, I'll have to check it out

thanks