When it comes to popular music, it's hard to overlook the influence of the blues. You can hear it in everything from Led Zepplin to Nora Jones. It has also had a huge effect on jazz, pop and many types of folk music. There are a number of ways that you hear these effects. One of them is on chord progressions used in songs. Most people think that this is simply a matter of the I-IV-V blues form but it goes way beyond that. Today we'll look at some of the other common blues type progressions.
I-bIII-IV
This is the one that's used in all types of music from metal to dance. Some may think that it's a version of a minor chord progression but the main difference is the melody is a major scale played over the progression. A number of scales can be used over this progression; the major, blues and mixolydian scales are all available. This progression is used in two ways. First it's often used as the main idea in a rock song, usually played with a riff or reocurring line. It's also used in sequences where you would use a I-bIII-IV using the I chord and then transpose the entire progression up a fourth to be used over the IV chord. For example a E-G-A progression to a A-C-D progression.
I--IV-bVII-I
This is another progression that seems like it's 'borrowed' from the minor but like the progression above, it's used for major, minor and blues melodies. The bVII is often interjected into diatonic chord progressions but when used in this context it takes on the function of the V chord and pulls the harmony back to the I. Diatonic chords can be used with this progression but you'll often find that the progression on it's own pulls you in a more rock/blues direction.
I7-IV7-V7
You can hear the blues influence in this progression right from the first chord. Unlike a modal progression, all of the chords are dominant 7th which has a somewhat more 'unstable' sound than the straight major I. A number of scales can be used with this progression including blues, minor or major pentatonic, mixolydian, and major. Also, the b7th note in each chord may be used in the melody as a 'blue' note adding more interest. The progression is the core of the blues.
I7#9-bIII-IV
This the famous 'Jimi Hendrix chord'. Although used by many musicians, Jimi was the one that arguably made it famous. Sharp 9 chords are great for blues because they contain the natural 3 (from the harmony) and flat 3 (from the blues scale). Both rock and jazz musicians alike use this chord extensively when playing the blues as it tends to have more of a 'bluesier feel' than straight 9 (and especially b9 which lends more to a minor blues progression). The bIII and IV are added to finish off the progression although the sharp 9 chord will work with any blues progression.
I7-IV7-I-bVI-V7
This an added chord to end of the IV-V. A bVI chord is added to the turnaround to add a bit of spice. All of the chords in this example are major.
Im-IVm-V7(b9)
This the minor blues. There are many variations of this. The minors replace the majors in your standard blues progression. The flat 9 may or may not be used; it simply reinforces the minor sound. Minor 7ths may also be used.
Im-IVm-bVI-V7
Another variation of the minor blues. Often the bVI is added for a little more variety. Jazz musicians often take these progressions and add ii-V's and secondary dominants throughout the progression. Musicians like John Coltrane are famous for making up their own special variation of blues changes.
Just The Beginning
There are numerous variations of the blues. Too many to mention in this post. Any of the progressions listed above may be used in a 12 bar blues format or on their own. Many of these appear in pop, country and jazz tunes. There is no limit to the variations or ways in which you can use them. Take one at a time and explore the possibilities.