Most sixteen bar blues are adapted from a standard twelve-bar progression. The standard twelve-bar blues progression is where each cell in the table represents one measure, "I" represents the tonic chord, "IV" the subdominant chord, and "V" the dominant chord. Twelve-bar progressions are formed by applying one of several formulae, including the following. One adaptation extends the first section of tonic chords by doubling or repeating to become the first half of the sixteen-bar progression, Examples include "I'm Your Hoochie Coochie Man", "Close to You", written by Willie Dixon and first performed by Muddy Waters, and "Oh, Pretty Woman", written by A.C. Williams and first recorded by Albert King. Instead of extending the first section, one adaptation extends the third section. Here, the twelve-bar progression's last dominant, subdominant, and tonic chords are doubled in length, becoming the sixteen-bar progression's 9th–10th, 11th–12th, and 13th–16th bars, Examples include "Trigger Happy" by "Weird" Al Yankovic. Instead of extending the first or third section, one might repeat the second section. In this version, the twelve-bar middle section is repeated, often along with its lyrical-melodic material: Examples include "rural" versions of "See See Rider" ; most renditions of ":wikisource:Going Down The Road Feelin' Bad|Going Down The Road Feelin' Bad" AKA "Lonesome Road Blues", e.g. by Henry Whitter, the Blue Ridge Duo and Woody Guthrie; and "Sleepy Time Time" by Cream. In a further repeating variation, the transition from the ninth to tenth twelve-bar chord is repeated twice, This can be heard, for example, in "Watermelon Man" by Herbie Hancock. In a final style, the transition from ninth to tenth twelve-bar chord is repeated once and the last tonic chord bars are doubled in length, Examples include "Let's Dance," written by Jim Lee, first performed by Chris Montez, and covered by bands including the Ramones.
Adaptation from eight-bar progression
Alternatively, a sixteen bar blues can be adapted from a standard eight bar blues by repeating each measure of the eight-bar progression and playing the result at double speed.
