In essence, Western Jazz and pop music share some of the same elements, but are very different. Basically, the Western Swing era is a specific movement that emerged in the late 1950s amongst primarily blue-collar American native musicians who moved to the often more cosmopolitan United States from their original musical roots in eastern Europe, Asia, and Africa. It’s characterized by a mix of many influences from popular music from all genres including jazz. One of the biggest influences was ragtime, which was a genre developed by African-American and white hype musicians during this period. Many would later come to call it simply swing.
What distinguishes it? Essentially, its main difference lies in the lead guitar player’s use of tonal material. In jazz, for example, you’ll hear a lot of repeated bass line, or sustained chord melody (sometimes referred to as “disco” music), on top of which is a lead line (a phrase that plays at the end of the bar or verse). While this may be evident in popular music, which has the lead and the refrain (the refrain being a repeated note, chord, or scale tone), it’s less prevalent in jazz where the melody predominates. Instead, the lead guitarist (also known as the rhythm guitarist) uses fills and alternate picking. Fill passages often repeat notes in a scale or chord progression.
Why was this difference important? Well, it made it easier for the lead guitarist to provide a rhythmic “anchor” that allowed the rest of the band to vary and progress without having to repeat the same note over. For example, a long bluesy bar can easily become a minor lead power chord in a major rhythm guitar groove if the lead guitarist repeats bar chords (or even a minor chord on top of a major chord). On the other hand, a minor bluesy bar can quickly become a major lead power chord if the lead guitarist goes on a long double-time fill. This is simply because the bluesy bar (with an underlying minor melody) is repeated by the rhythm guitarist, who in turn, uses fills. This cycle continues indefinitely.
So how does a lead guitar player to break this cycle? Well, the answer lies in learning how to use the entire neck of the guitar for notes (and not just the pick) and also understanding how rhythm guitarists apply technique. If the lead guitarist can isolate a single pitch (the note of a bar or verse), then he can use that pitch in all of his films, whether he’s playing a bluesy bar or using a classic rock rhythm. As a result, the entire neck of the guitar is used for notes, rhythm, and technique. As a result, the guitarist becomes a multi-faceted guitarist.
Here’s another example. A major jazz chord is achieved by picking up a note (A), raising the pitch (B), and striking the sixth string (C). The note E is the next highest note after A. Because it’s the highest note, it is used as the first note in a jazz song, or a solo. A similar situation occurs when you play a minor jazz chord. Rather than using A and C, the higher notes are played, which creates a minor bluesy sound.
As stated earlier, there are some commonalities between western and pop music. In terms of melody, many of the same rules apply. For instance, the bass line in a rap song often uses the G and C notes that are found in jazz chord melody. (This is especially true in hit songs by artists such as Kanye West, Rihanna, etc.) In pop music, a similar rule applies: A major melody (a bar or verse) is played on the beat, with the bass line providing the melody.
The lead guitar in jazz and pop music also follows a similar format. A lead guitarist uses pentatonic scales to create the basic backing line. Sometimes the lead guitarist will use arpeggios, using the notes from the backing to provide a variety of rhythmic variations.
Interestingly enough, there is a lot of crossover appeal between the two music styles. Both use many classic guitar lines (such as the F#maj7 chord in jazz), and both use similar melody formats (A major and E minor in pop music). These similarities tie into the question of whether or not these genres are “real” music. Do they contain purely “verbal” elements, or are they “genuine” music? It’s a question that continues to be argued by many scholars, but in general, the answer seems to be “no”.