Let’s explore 7th intervals, which sound wide and angular.
In 1972, bassist John Wetton (pictured above) joined a new incarnation of the progressive jazz-rock-fusion-experimental band King Crimson, which was led by the brilliant guitarist and composer Robert Fripp. The band stills holds a place in the pantheon of seminal jazz-rock fusion bands of the era, alongside Genesis, Weather Report, Mahavishnu Orchestra, and some of Miles Davis’ electric jam bands. When I first heard “Larks’ Tongues in Aspic, Part II” [King Crimson, Larks’ Tongues in Aspic, Island, 1973], I was struck by the power of Wetton’s bass line. What are those notes—that wacky interval he’s playing?
With some help from my slightly older, more experienced bandmates, I eventually cracked the code of the song, and we came up with our own version of “Larks’ Tongues.” The interval that had me puzzled? The notes F down to G—a minor 7th interval (Ex. 1).
Wetton’s bass line is unique because of the relentless repetition of the minor 7th interval in the first two bars, with no other notes involved. Many bass lines use a minor 7th interval as part of a string of notes, but Wetton’s line hammers away at the F and G. Add that to Fripp’s Bartók-like melody and song form, and it’s unforgettable. When I began thinking of bass lines that incorporated the minor 7th, Wetton’s line came to mind first, even though I hadn’t heard it in about 40 years. That’s staying power in bass-line world!
The minor 7th interval—for example, F on the D string down to G on the E string—does not sit so well on the fingerboard. Playing the two notes of a minor 7th in quick succession demands the use of either two fretting-hand fingers (Ex. 2), or a barre, which holds down two notes with one finger (Ex. 3). In this case, the F and G could be held down with the 1st finger across the strings.
Bass lines that incorporate a minor 7th interval can be found everywhere, often as part of a sequence or melodic bass line. In 1966, James Jamerson laid down a beautiful groove for the Four Tops’ “Shake Me, Wake Me (When It’s Over)” [On Top, 1966]. Example 4 shows Jamerson jumping from a low Ab up to Gb on the D string. When you play this one, be sure to accent the high Gb, and don’t shortchange the eighth-rest that follows.
Flea came up with a dangerous-sounding, acrobatic line that incorporates the minor 7th interval on “Give It Away” [Red Hot Chili Peppers, Blood Sugar Sex Magik, Warner Bros., 1991]. Flea’s line starts on an open A, and then slides from high E on the G string up to a high G, an octave plus a minor 7th away from his starting note (Ex. 5).
How can you get 7th intervals under your fingers? The best way is to explore the possibilities within scales and chords. Example 6 shows an F major scale in 7th intervals. Note that some of the intervals are major 7ths (marked “7” in the notation) and some are minor 7ths (m7). You can build a major 7th interval from any note by counting up or down eleven half-steps. You can build a minor 7th interval from any notes by counting up or down ten half-steps.
If you stay within a key signature or scale, you merely have to count up to the scale’s 7th note to find a 7th interval within that scale sound. You can also think of the minor 7th interval as the distance from the root to the top note of a 7 chord (Ex. 7), while the major 7th interval is the distance from the root to the top note of a maj7 chord (Ex. 8). Once you become familiar with the way major 7ths and minor 7ths sound and feel on the bass, you’ll automatically grab the correct notes.
Another great way to master 7th intervals is to create your own bass lines, forcing yourself to use a particular 7th interval. Example 9 shows a bass line that starts on Bb and jumps down to the root of the C7 chord—a minor 7th interval. Although the line begins on Bb (the flatted 7th), it lands on the root, C, in both bars.
Play through the examples, and then create some of your own lines using 7th intervals. Maybe you’ll come up with something like “Larks’ Tongues,” which bass players will still be talking about four decades later!.