There are two accepted sets of notes for blues. Scales if you like. There's the more common minor blues - C Eb F Gb G Bb, and there's the major blues C D Eb E G A - each based on the minor and major pentatonics - which, just like major and relative minor, will match two keys. Take that first minor blues - the notes are exactly the same as those in the Eb major blues. Take the second set - those notes are the same as Am pent. The whole of the unison part of Sir Duke uses major blues notes only. Boring and static?

@Tim Sir Duke is neither boring nor static, nor does it have much to do with Blues.

@leftaroundabout - all I'm pointing out is that Ben's 3rd para. states just that. It's not true, and you've agreed with me. Nothing wrong with using Blues notes for non-Blues songs, is there?

I have to agree with Ben's sentiment here - the so-called blues scale and blue note are simplified approximations made in order to represent something that's a bit alien to the Western music tradition for which the scales and notation system were created. And the equal temperament system. Notes are supposed to be bent in blues, and it feels a bit fake when someone plays the "blue note" very clearly, like a sentence learned on a foreign language course. "This is rock and roll" youtube.com/watch?v=ala6uqCFOJ0&t=67s

I think this is spot-on too - Blues playing is about bending notes through ranges, not about an identifiable set of notes: music.stackexchange.com/a/31074/18896

There are piles of theory books, etc. describing the major and minor blues scales. As theoretical constructs, they're extremely well-established. In music, they're extremely common and widely used. BenCrowell and @topomorto, do you have any references supporting the view you describe? Otherwise it seems like a fringe view, and it's one I have not encountered and strongly disagree with. Sure, anything can be made to sound bad if overused, but that doesn't make the blues scale theoretically weak or unjustified.

I agree 100% with @jdjazz here. "Jazz, blues, and rock and roll music doesn't really build melodies out of such a scale.": the first thing that comes to mind for me is the jazz blues "Bag's Groove," which has a theme built entirely from a minor pentatonic scale. "...it tends to sound boring and static if you never recognize the changes in harmony...." Continuing with "Bag's Groove," the 12-bar theme is repeated three times without any change, other than that the underlying chords are changing. This actually seems pretty emblematic of the blues, to me.

@jdjazz emusicology.org/article/view/6316/5180 is one example of a work going into the idea of blue notes as a "range". But what exactly is the point that you're querying?

@leftaroundabout, this question isn't about the blues genre or the 12-bar blues form. It's about the blues note, which Tim astutely points out is used widely in many other genres. He's saying that Sir Duke is a counterexample that directly rebuts Ben's statement that "music doesn't really build melodies out of such a scale." This section from Sir Duke does build a melody from the major blues scale.

@topomorto, I was taking issue with these statements: (1) "music doesn't really build melodies out of such a scale," (2) "blue note are simplified approximations ... [because] notes are supposed to be bent in blues," and (3) "blues playing is about bending notes through ranges, not about an identifiable set of notes." I disagree with the implication that the blues note isn't useful simply because that note is sometimes bent. (Are we prohibited from writing the b7 in scales because that note is occasionally bent in blues songs?)

@topomorto, but setting this aside, the bigger issue I have is that the blues scale is used in far more contexts than just the blues genre. The quoted statements seem to ignore those other contexts outside of blues. The original question doesn't mention the 12-bar blues form or blues as a genre. In music generally, the "blues note" is widely used, and it's a broadly accepted theoretical construct.

@jdjazz - with you all the way! Seems to be semantics are taking over! 'Notes are supposed to be bent in Blues' basically means Blues cannot be played on piano or organ. And there are lots of Blues guitar and sax pieces with hardly a bend in them... What?

@Tim you beat me to mentioning piano - piano blues is of course the place where you could talk about a scale of discrete notes. But in a way, it's the exception that proves the rule, because piano isn't the archetypal blues instrument. Put it this way - if notes could have been bent on piano 100 years ago, they would have been when playing the blues (IMO!)

@topomorto - I get round it on piano by using 'crush' or grace notes, which is as close as you can get. I wonder if anyone has actually worked out what the 1/4 or 1/2 bends are on guitar. I know on tab it will show - but how exact is it..?

@jdjazz statement 1) does sound absolutist, but then you have cut half of it off! Statement 2) There may be some contexts where you can't bend notes, but if you teach someone blues guitar or singing without teaching them to bend through ranges, you're doing it very wrong. To say that a blues note is "sometimes bent" doesn't go far enough to me - to quote the source I linked, It is widely acknowledged that the three blue notes must be "bent" in pitch from a standard note played on a host instrument using 12 tone equal temperament tuning.

@jdjazz as for 3) - The problem is writing 'b7' is if it's done without imparting the knowledge that bending it may be appropriate. A blues musician needs to understand those ranges around the third, fourth, and seventh. As long as they're understood, the actual notation is secondary, but the problem with the idea of a blues scale that's simply a selection of discrete notes from the chromatic is that that knowledge can get detached.

@Tim excellent point about 'crush'/grace notes. You do have to play the blue notes on piano with a certain touch and timing for them to 'work' - usually, that touch and timing has to be such that it is an approximation of a bend on a non fixed-pitch instrument.

On the general point about major and minor blues scales being well-established theoretical constructs - well yes they are, but I believe that is related to the idea that music can be either "major" or "minor". That idea itself is well-established, but ultimately it's a simplification, and as you progress, you learn that the reality is a bit more complex. Same with the blues scale IMO.

@topomorto - the idea that music can be maj or min is pretty well flawed anyway, and most blues players will use the notes from the two parallel scales regardless, so it's not a problem. Yes, the notes are fairly well established - there are guitar exams where one is expected to play certain blues scales, so it's official - in that way.

@Tim yes, simplifications are fine, as long as it's understood that that's what they are. In the context of this question, where we're talking about how you would do chord building based on the concept, I think it's valid to point out that the blues scale "isn't that type of scale". As user45266's answer says, "The real beauty of the blues scale is its melodic capabilities" - and that beauty is largely because of those bends (or other inflections) in the ranges of the third, fourth, and seventh.

Incidentally en.wikipedia.org/wiki/Blues_scale points to some of the struggles with defining a blues scale as a set of discrete notes. "a blues scale may be considered to not fit the traditional definition of a scale".

@topomorto, if we agree to limit the statements about bending, etc. to early blues music (just as the article you cite does), I have no problem at all. Obviously Sir Duke is not early blues, and so I'm thinking about the broader implications of these claims. I disagree that the blue note "must" be bent in all subgenres of jazz, rock and roll, and blues. The statements on this site haven't specified the same limited context as the article you cite.

@topomorto, context is relevant too. The Q isn't about early blues--it's about the blues scale generally. It sounds like you'd agree that some later genres, which are far removed from early blues, use the blues scale (or their version of it) differently. I don't want to take these legitimate historical claims about early blues and apply them broadly to all forms of jazz, rock, and blues. The OP may not be working in the blues genre at all. Regarding jazz, we can't make the same claim that the piano was added later. And in up-tempo bebop songs, are the horns still required to bend blues notes?

@jdjazz I would tend to agree with leftaroundabout that Sir Duke is far from being a blues piece IMO; following from that, I don't personally see it as having much relevance to the definition of the blues scale. Of course if you do think of it as blues, I appreciate you'll take a different view - but there are a lot of much more recent songs that retain the 'bendy' nature of blues, so I'm not sure that the 'early'/non-'early' distinction helps.

I do agree that saying that notes 'must' be bent in blues is going too far. But by the same token, I think that only saying that notes in blues can be bent, or are sometimes bent, isn't going far enough - the idea of sounded notes exploring ranges of pitch is fundamental to the execution of blues.

The OP may not be working in a blues genre, but I'd suggest that in the majority of cases where it's reasonable to talk in terms of the blues scale, note bending will be a feature. It's certainly a feature of bebop work.

I'd say the bending is more of the expression of blues rather than the definition of the notes used in blues. It's a technique used to give an effect and it is greatly tied to the tradition, but trying to say the scales aren't well defined because bends are used with the blue note is a little too far.

I agree completely with Dom. Also, the question here isn't whether bending is a "feature." If that's all you're claiming, then I'm on board. But the article and earlier statements suggest a requirement. You've been talking about 'not bending' as an exception to the rule.

Talking about a "majority of cases" is impossible, because readers will have vastly different experiences and will play in different genres. At any rate, it's likely impossible to look at all instantiations of music and attempt to quantify the fraction of scenarios where notes are vs. aren't bent. The point is that context is needed, and the earlier statements seem to articulate strict rules that simply fail to describe all scenarios.

@topomorto, your comments about Sir Duke imply that the blues scale only exists when played in blues music. I'm not following that logic. If blues players improvise on the notes C-D-Eb-E-G-A, then this counts as the blues scale, but if other players improvise on those same notes, then it's not the blues scale?

@jdjazz It's not about the player, but the style of playing. I'm saying that the notion of a blues scale isn't particularly useful without an understanding of the expressive techniques associated with blues playing.

From this book: amazon.com/dp/B00FJ6E5NS/?tag=stackoverfl08-20

"Actual blues melodies defy traditional musical notation by including sounds that literally fall between the notes on the staff"

If the blues scale had existed before the playing style, we might look at things a different way.

@topomorto, the point about 'different players' is that different readers of the site will play in different genres. Any claims that are not true in general need to be qualified since we don't know what context they'll be working within. Failing to specify "early blues" will result in some people walking away applying those narrow claims more broadly than they are intended.

@topomorto, so you agree that anyone who uses the notes C-D-Eb-E-G-A to improvise or compose is building their melody from the C major blues scale? Even if they don't work in the blues genre?

Consider the following statement: "the unison section of Sir Duke is built from the B major blues scale." You argue that this statement isn't useful because the musicians aren't bending notes in the same fashion found in early blues?