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~~Lord Larehip~~ · 11-15-2014, 01:15 PM

The most basic blues structure is 12-bar blues. To explain what this means, I must explain some rudimentary music theory. A bar is another name for a measure which is a specified grouping of notes, rests or beats between two vertical lines on a musical staff. A note on that staff represents a beat during which a tone is played while a rest is a beat during which no tone is played (the beat, however, is internal and not necessarily audible). Take a piece in common time, which is 4/4 time, which means there are four beats to a measure and that the quarter note (or crotchet) gets the beat. So a single measure or bar can have a maximum of four crotchets, which represent four beats, and then the next measure starts. A bar can also have eight eighth-notes (or quavers) since an eighth-note represents half a beat in 4/4 time so we can have twice as many quavers in a bar as we can have crotchets. A measure of 4/4 can also have two half-notes since a halfnote
is two beats or it can have a single whole note which represents four beats. We can combine various notes such as three crotchets and two quavers which total out to four beats (1/4 + 1/4 + 1/4 +1/8 + 1/8 = 4/4). Or four quavers, one crotchet and one crotchet-rest which also totals out to four beats. Whatever note and rest combination totals out to four beats represents a bar of music in 4/4 time. In 3/4 time, there are three beats in a measure with a quarter note representing the beat. In 3/8 time, there are three beats in a bar with an eighth-note representing the beat and so on. But blues is in 4/4 time.

In the basic blues structure, the entire set of chord changes is contained in 12 bars with the changes occurring at I, IV and V or at tonic, subdominant and dominant. In the following table, each Roman numeral represents a bar of that scale degree. Follow from left to right for each successive row:

I I I I
IV IV I I
V IV I V7

This table is very basic. The V7 at the end indicates that the V chord should be played as a seventh-chord. The reason is that seventh chords have a bluesy sound that make them ideal for resolving the blues progression at the end. We are forced to substitute a dominant 7th chord (consisting of root, perfect 3rd, perfect 5th and flatted 7th) shown here instead of the “blues seven” which has an approximate 7:4 ratio which is not found in Western music theory is but is close to a dominant 7th. The last bar or two is called the “turnaround” because it starts the 12-bar cycle from the beginning although a turnaround can occur before each new progression within the 12 bars by using the dominant seventh (V7). The beauty of the blues structure is that it can be sliced up and diced up and reassembled in a nearly infinite variety and still sound like blues. Likewise, we don’t have to stick only to 12-bar blues. Some blues is 8-bar and some is 16-bar and still it sounds like blues.

Hart Wand’s “Dallas Blues” mentioned earlier was a standard 12-bar blues. So the form had been around for some time as it is doubtful that Wand invented it and “Dallas Blues” is a far cry from Delta blues and yet there are definitely similarities.

Bill Doggett’s 1956 hit “Honky Tonk” (which received a resurge in popularity after being featured in the movie Blue Velvet), is a 12-bar blues that uses the following structure:

I IV I I
IV IV I I
V IV I V7

Note the use of the subdominant in the second bar instead of repeating the tonic. Yet, who would argue that “Honky Tonk” is anything but a 12-bar blues?

Bill Doggett Honky Tonk Pts. 1 and 2.wmv - YouTube

The blues scale, which technically is not a scale, is quite different from the major scale because III, V, VII are flatted and are called blue (or bent) notes. They are approximated in theory as half-step flats when, in reality, they are slightly less than a half-step which can’t be shown in standard notation which does not allow for notes less than a half-step. For that same reason, the dominant 7th is substituted in theory for the "blues seven."

Even odder, while the flatted 3rd and 7th replace the natural 3rd and 7th, the flatted 5th does not have to replace the natural 5th in a blues piece but can alternate with the natural 5th throughout the course of the piece. The bent 5th can be inserted when it “feels right.” Blues is also unique in that playing two adjacent notes (a half-step apart) simultaneously is allowable and adds to the melodic line rather than sounding like a mistake. Then there
is the use of the slide to glide from note to note.

Blues, rock, jazz and country are often played in the minor pentatonic scale. In this scale, II and VI are removed (they are so seldom played that we can simply omit them altogether) leaving just five notes including the flatted 3rd and 7th but the 5th is listed as natural but, in reality, shares its position with the flatted or bent 5th. Strictly speaking, the blues scale is not a minor scale but what is called a “forced minor,” i.e. the blues scale is a minor scale “forced” or imposed over a major scale. The bent 5th gives blues its emotion. The flatted 3rd and 7th gives blues its raw, dark sound.

Just to further confuse you, even though I said earlier that blues is in 4/4 time, that isn't really true because the melodic lines of blues are generally arranged in triplets, which represent a way of dividing a measure of 4/4 time into four beats with eighth-notes grouped into threes. They are counted as “one-trip-let-two-trip-let-three-trip-let-four-trip-let.” For this reason, standard 12-bar blues time is usually 12/8 rather than 4/4 but it's easier to count as 4/4. Make sense?

To drive home the point, listen to the intro of T-Bone Walker's 1947 hit, "Bobby Sox Baby":

T Bone Walker - Bobby Sox Blues - YouTube

The guitar plays "one-triplet-two triplet-three" and the kick drum finishes it off with "triplet-four-triplet". The guitar and drum repeat this in the next bar. Then guitar plays "one-triplet-two-triplet-three-triplet-four-triplet-one-triplet-two-triplet-three". Then the song enters the main theme which is 12-bar blues with a scheme of

I IV I I
IV IV I I
V V I I

Walker doesn't end the last bar with a V7 because he then launches into a bridge rather start repeating from the first bar. However, he could have played a V7 and still gone into the bridge and it wouldn't screwed up the song. He probably avoided the V7 simply to avoid sounding too generic. As I said blues structure is quite malleable and still remains blues.

11-15-2014, 01:15 PM	#10 (permalink)
~~Lord Larehip~~ Account Disabled Join Date: Jun 2013 Posts: 899	The most basic blues structure is 12-bar blues. To explain what this means, I must explain some rudimentary music theory. A bar is another name for a measure which is a specified grouping of notes, rests or beats between two vertical lines on a musical staff. A note on that staff represents a beat during which a tone is played while a rest is a beat during which no tone is played (the beat, however, is internal and not necessarily audible). Take a piece in common time, which is 4/4 time, which means there are four beats to a measure and that the quarter note (or crotchet) gets the beat. So a single measure or bar can have a maximum of four crotchets, which represent four beats, and then the next measure starts. A bar can also have eight eighth-notes (or quavers) since an eighth-note represents half a beat in 4/4 time so we can have twice as many quavers in a bar as we can have crotchets. A measure of 4/4 can also have two half-notes since a halfnote is two beats or it can have a single whole note which represents four beats. We can combine various notes such as three crotchets and two quavers which total out to four beats (1/4 + 1/4 + 1/4 +1/8 + 1/8 = 4/4). Or four quavers, one crotchet and one crotchet-rest which also totals out to four beats. Whatever note and rest combination totals out to four beats represents a bar of music in 4/4 time. In 3/4 time, there are three beats in a measure with a quarter note representing the beat. In 3/8 time, there are three beats in a bar with an eighth-note representing the beat and so on. But blues is in 4/4 time. In the basic blues structure, the entire set of chord changes is contained in 12 bars with the changes occurring at I, IV and V or at tonic, subdominant and dominant. In the following table, each Roman numeral represents a bar of that scale degree. Follow from left to right for each successive row: I I I I IV IV I I V IV I V7 This table is very basic. The V7 at the end indicates that the V chord should be played as a seventh-chord. The reason is that seventh chords have a bluesy sound that make them ideal for resolving the blues progression at the end. We are forced to substitute a dominant 7th chord (consisting of root, perfect 3rd, perfect 5th and flatted 7th) shown here instead of the “blues seven” which has an approximate 7:4 ratio which is not found in Western music theory is but is close to a dominant 7th. The last bar or two is called the “turnaround” because it starts the 12-bar cycle from the beginning although a turnaround can occur before each new progression within the 12 bars by using the dominant seventh (V7). The beauty of the blues structure is that it can be sliced up and diced up and reassembled in a nearly infinite variety and still sound like blues. Likewise, we don’t have to stick only to 12-bar blues. Some blues is 8-bar and some is 16-bar and still it sounds like blues. Hart Wand’s “Dallas Blues” mentioned earlier was a standard 12-bar blues. So the form had been around for some time as it is doubtful that Wand invented it and “Dallas Blues” is a far cry from Delta blues and yet there are definitely similarities. Bill Doggett’s 1956 hit “Honky Tonk” (which received a resurge in popularity after being featured in the movie Blue Velvet), is a 12-bar blues that uses the following structure: I IV I I IV IV I I V IV I V7 Note the use of the subdominant in the second bar instead of repeating the tonic. Yet, who would argue that “Honky Tonk” is anything but a 12-bar blues? Bill Doggett Honky Tonk Pts. 1 and 2.wmv - YouTube The blues scale, which technically is not a scale, is quite different from the major scale because III, V, VII are flatted and are called blue (or bent) notes. They are approximated in theory as half-step flats when, in reality, they are slightly less than a half-step which can’t be shown in standard notation which does not allow for notes less than a half-step. For that same reason, the dominant 7th is substituted in theory for the "blues seven." Even odder, while the flatted 3rd and 7th replace the natural 3rd and 7th, the flatted 5th does not have to replace the natural 5th in a blues piece but can alternate with the natural 5th throughout the course of the piece. The bent 5th can be inserted when it “feels right.” Blues is also unique in that playing two adjacent notes (a half-step apart) simultaneously is allowable and adds to the melodic line rather than sounding like a mistake. Then there is the use of the slide to glide from note to note. Blues, rock, jazz and country are often played in the minor pentatonic scale. In this scale, II and VI are removed (they are so seldom played that we can simply omit them altogether) leaving just five notes including the flatted 3rd and 7th but the 5th is listed as natural but, in reality, shares its position with the flatted or bent 5th. Strictly speaking, the blues scale is not a minor scale but what is called a “forced minor,” i.e. the blues scale is a minor scale “forced” or imposed over a major scale. The bent 5th gives blues its emotion. The flatted 3rd and 7th gives blues its raw, dark sound. Just to further confuse you, even though I said earlier that blues is in 4/4 time, that isn't really true because the melodic lines of blues are generally arranged in triplets, which represent a way of dividing a measure of 4/4 time into four beats with eighth-notes grouped into threes. They are counted as “one-trip-let-two-trip-let-three-trip-let-four-trip-let.” For this reason, standard 12-bar blues time is usually 12/8 rather than 4/4 but it's easier to count as 4/4. Make sense? To drive home the point, listen to the intro of T-Bone Walker's 1947 hit, "Bobby Sox Baby": T Bone Walker - Bobby Sox Blues - YouTube The guitar plays "one-triplet-two triplet-three" and the kick drum finishes it off with "triplet-four-triplet". The guitar and drum repeat this in the next bar. Then guitar plays "one-triplet-two-triplet-three-triplet-four-triplet-one-triplet-two-triplet-three". Then the song enters the main theme which is 12-bar blues with a scheme of I IV I I IV IV I I V V I I Walker doesn't end the last bar with a V7 because he then launches into a bridge rather start repeating from the first bar. However, he could have played a V7 and still gone into the bridge and it wouldn't screwed up the song. He probably avoided the V7 simply to avoid sounding too generic. As I said blues structure is quite malleable and still remains blues.