Answer to Question 1All the other examples in the chapter have been in major keys where the important chords (I, IV, V) have a major thirda musical interval/distance of two whole steps--between their first and second chord tones1. For example, a major chord built on C is made up of the tones C E G (C to E is a major third). However, in Ain't Enough Comin' In, which is a
minor blues, the important i, iv and v chords of the piece are minor chords built with lowered (flatted) or minor thirdsa musical interval/distance of one and half whole steps--between their first and second tones. Using minor chords gives the music an entirely different quality from songs using the major I, IV, and V chords. For example, a minor chord on C contains the tones C Eb G (C to Eb is a minor third). Play these two chordsC major (C E G) and C minor (C Eb G)on any keyboard and you will immediately recognize them and their distinctly different chord qualities.
1 Assuming the chord is stacked in root position, that is, presented with the chord tones stacked in order from lowest to highest pitch.
two quicker notes/units that are equal in length
In the shuffle beat heard in other examples, the beat is divided into . . .
three quicker notes/units, in which the first two notes/units connect together to create
a long-short (shuffle pattern).
Stablizing Selection
The clonal selection hypothesis
Gangrene of the toes and foot as a result of an infection often means eventual amputation.
Better land and water management and appropriate crop selection can help eliminate hunger
Beak size in finches during dry years increases because of strong selection
Directional artificial selection favoring the AdhF allele in experimental Drosophila populations.