Guitar Lesson : Pentatonics and Passing Tones
Monday, July 30, 2007
By Stephane Brault
A passing tone is a melody note that falls between two consecutive chord tones or scale degrees. For example, if you were to take the two first notes of the C major scale, C and D, and play C# (C sharp) between them, the C# (which may also be reckoned as Db or D flat) would also function as a passing tone as demonstrated in figure 1.
The passing tone is a melodic stepping stone that's very useful for sculpting the shape of a line and filling in rythmic space within a beat while avoiding melodic redundancy.
Figure 2 is an example of a walking bass line that uses passing tones to smoothly bridge the gaps between the chord tones. Notice how the passing tones in this example serve as transition notes that help give the line a satisfying contour and complete the moving quarter-note pattern without repeating any notes.
The minor pentatonic scale is spelled 1, b3, 4, 5, b7 ("one, flat three, four, five, flat seven"). If you were to add a passing tone between the fourth and fifth degrees of this scale, you would then be playing the six-note minor blues scale, spelled 1, b3, 4, b5, 5, b7.
Figure 3 shows both the E minor pentatonic scale (E G A B D) and its chromatic mutated cousin, the E minor blues scale (E G A Bb B D). As indicated in the footnote below, the added b5 (flat five) scale degree may alternatively be considered the #4 (sharp four), in this case, A# instead of Bb. Whether you call it a b5 or a #4, this added musical chromosome is often referred to as the "blue note".