when to use a minor 3rd in a non-minor tune

There are major and minor 3rds in all of our western scales and modes, so it's just a matter of using ones that are diatonic i.e. B to D in a Gmaj chord is a minor 3rd; D to F is a minor 3rd in G mixo.

 

I think it's fine in certain cases. Especially if the numbers are bluesy as you mentioned. Blues is a mixed up kind of thing. It's neither major or minor really. If it's a major chord, don't be scared to throw in a minor 3rd to add interesting spice. But, as with everything, moderation is key. For that matter, just say you're in a major key, on the I chord, it's a blues, or at least bluesy, number, chuck in a flat 7, flat 5, minor 3rd. See what works, see what doesn't.

 

If the minor 3rd is acting as a passing tone, leading to the 2nd or the major 3rd, it probably works in a major 3rd tonality. But if you sit on it and try to play it as a chordal note, it will sound wrong. IMO.

 

I tend to use the major third as a passing tone, particularly when walking up to the fourth. I like to use the minor third for that somewhat dissonant bluesy sound. Particularly over dominant chords.

Of course, the main rule to follow is that if it sounds good it is good.

 

+1

 

Here's another way to think of this, assuming I understood your question correctly: Minor melodies over major chords are definitely one of the key components of blues and blues-based music. But that "minor third" isn't really that but an augmented ninth, put on top of a dominant seventh chord. If you take the three chords that make a blues progression in C, you have:



And adding an augmented ninth on top, you get...



But you know that Eb, Ab and Bb are enharmonic equivalents of D#, G# and A# (the top notes), so, and although technically speaking it is not a correct statement, it could be said that those chords have both major and minor thirds. I don't know if that practice/effect has a different name in English (since I haven't seen it), but translating from Spanish to English, it's called a broken third effect. That's what gives the blues-based music its typical character and sonority: A "minor" melody played over a major chord progression.

There's a simple rule in composition/arranging that makes this possible: You can have for sure that practically any extension you want to try for a dominant chord will work fine (which doesn't necessarily happen on any other type of chords). One of the reasons for that is because dominant chords are the most "natural" ones (using the term in contraposition to "fabricated") because of the harmonic overtone series. That's why, in theory (I mean, assuming you have some basic phrasing and melodic skills), almost anything you play/improvise over a blues chord progression will sound fine: All three chords have a dominant quality and, again, those are the most flexible ones if you want to "extend" them with good results. Perhaps the only thing you must be aware of is that "weird" notes work much better on the instrument's mid-high and high registers.

Hope this helps. BTW, I want to mention that it's pretty common here (and perfectly valid, of course) that most harmony-related explanations are based on scales and modes. While I consider to have an adequate (at least basic) knowledge of how scales and modes are built and how they work, I definitely tend to thnk more in terms of chords, as in this case.

 

^ That's a pretty good description
And to answer your question about a rule of thumb, there isn't one really. When it comes to blue notes it's all feel. Using a minor third as a passing tone to the major third is fine, also I respect WJGreer's opinion, but I think it can be sat on. Well maybe not sat on but used as something more than a passing tone. In a major blues progression, I would use a minor 3rd more commonly than a major third. Just cause that's the sound I like. The major 3rd should be covered by other instruments, you add that soul food Don't worry about rules of thumb, just use your 1 2 b3 4 b5 5 b7 8 blues scale and maybe the odd major third. IMO of course

 

STICKING with your example of a 'B♭' sounding at the same time as a 'G Major Chord'... there are infinite examples of that happening.

Next, you have to decide if this pitch is really a B♭ or an A#. That definition is learned by what pitch follows.

A simple example, in a bass line, would be ascending quarter-notes connecting a G chord to a C chord: || G, A, A#, B | C || In this case the A# is a passing tone (non-chord tone).

Concerning a Dominant-Seventh-Augmented-Ninth chord (ex: G7#9): G, B, D, F, A#. It's an A# NOT a B♭. In this case the A# is a chord tone.

 

You mentioned one of your band mates picking up on your minor 3rd. And you got the fish eye.

Normally mixing minor and major, especially in a blues environment is quite alright, however any time you get a band mate's fish eye, probably best to re-think what works with this group.

If it sounds good it is good is the ultimate rule, however, with this band that does not look like it sounds good, so.........

 

Excellent explanation Alvaro. Although in the blues I think of it really as more of a flatted third than an augmented 9th.

The #9 gives a nice bluesy or "eastern" flavor to the line.
Or it can be a passing tone.
Or the tune can have a momentary modulation.
Or... sometimes it just sounds good with no need for analysis.

Use your ears. Play the line a couple of octaves higher and see if the minor third still sounds good. If it doesn't maybe it's "wrong". If it does, it works and there is probably some theoretical justification that says it's right.

 

You pretty much nailed it there. Bluesy songs often use the minor third (think both the major and minor blues scales)and the minor third is usually better than the major third in a sus-4 chord because the major third will clash with the 4.

 

Another way to think of it - when you are constructing a walking bassline or augmenting a blues line, it's better to approach roots by half step than by whole step, even if doing so means that you use a passing tone that isn't in the chord. As a general rule of thumb, approaching roots by whole step sounds square.

 

Country walking bass to the next chord will use chromatic runs and as such the b3 will get in that chromatic run - as will the major 3 as well.

If you are using chromatic runs (1/2 steps) I don't think you have to worry a lot about this.

G to C........ G-A-Bb-B-C that Bb being there has nothing to do with it being minor, it was just the next note in the walk. Of course IMHO..

 

You HO is correct. However, it's really an A# rather than a B♭ since, as you pointed out, [it] "has nothing to do with it being minor" and the A# moves UP - to the B.

 

In blues, it's not an augmented 9, it's the b3. Blues is based on non-western/European tonality. The sound that it's based on is a note between the major and the minor third. The juxtapoition of the two tones together is the way to get the effect with fixed pitch instruments.

John