Form | A section of a musical composition. Sections are determined by analyzing the harmonic and melodic content. They are generally 4, 8 or 16 bars in length (8 being the most common in jazz standards). These 8 bar sections are often labeled for quick reference, using letters of the alphabet chronologically. All duplicate sections are given the same letter. Some of the most common jazz forms are
Chorus | One time through the entire form.
Improvise | Spontaneous live composition. Also called soloing.
*It’s important to note that the improvised melodic and rhythmic lines are built of musical ideas (a.k.a jazz language) that the performer has often heard, played, and/or performed before. How they utilize and develop these ideas is extemporaneous in nature.
Trading | Two musicians soloing alternate solo sections (choruses or sections of the form).
Scatting | A vocalist’s use of nonsense syllables to create an improvised or planned melody.
Guidelines for Jazz Improvisers
Jazz musicians generally follow a set of guidelines. Of course, rules can be broken. However, not following the guidelines should be a conscious choice. In other words, a vocalist should not choose to break the guidelines until they can follow them beautifully and artistically.
Jazz Feel | There are many types of jazz feels (ex. triplet swing, straight eighth, Blakey march etc.)
Agreement | Performers that are part of a group must be in agreement on multiple aspects of the music; All band members must be in agreement on the tempo and band members must know exactly where they are.
Communication | Each member must communicate musically, which is evidenced by musicians hearing each other and responding in empathetic way.
Follows the Form of the Piece | When improvising a full chorus, the improviser must start the solo at the top of the form. When trading, all improvisers must begin and end their section within the form structure. For example, they can trade sections (commonly 8-bars each) or they can trade 1/2 sections (commonly 4 bars each).
Jazz Language | Utilizes melodic and rhythmic musical ideas (or phrases) common in jazz. This is often referred to as the jazz ‘language.’ For example, bebop rhythmic ideas are generally made up of eighth note lines that emphasize up-beats. Also, a swing melodic line generally outlines the chord tones underlying the melody in an interesting way. It can be referred to as ‘running changes.’
Different Types of Vocal Improv.
Melody-Guided Improvisation | the spontaneous creating of a melody based on the melody of the composition.
Melody-Guided Improvisation may be the spontaneous creation of a solo based on the original melody, or a substantial reinterpretation of the original melody. Whether the vocalist utilizes the lyrics or scatting syllable, the melody will still be recognizable in the melodic-interpretative improvisation style. Often the vocalist’s note choices settle in central tonalities of the original melody. This is different than paraphrasing, because there is still a focus on adding to and developing the melody with new content (musical ideas).
When the vocalist utilizes melodic-interpretive improvisation with lyrics the interpretation may be tied to literal storytelling. In other words, the performer is splitting their consciousness between interpreting the lyrics (or story) and developing the melody spontaneously. The improvisational aspect is heard in alterations to the phrasing as well as melodic embellishments and articulations.
This type of improvisation may also be executed without lyrics. This approach utilizes a technique unique to jazz known as scatting. Often the syllables used mimic musical instruments, such as the trumpet or saxophone.
Harmony-Guided Improvisation | the spontaneous creating of a melody based on the harmony of the composition.
When the vocalist utilized harmonic-interpretive improvisation the improvised melody is not tied to the original melody, or lyrics (although the sentiment of the lyric or arrangement should still be continued). The vocalists musical choices are based upon the chord progression underlying the melody.
Jon Hendricks explains Harmony-Guided Improvisation in my most recent master class video. Check it out!