Music Improvisation |12-Bar Jam track in A

Most musicians agree that improvising music along with other musicians, or even to a backing track, is a very enjoyable and creative thing to do, but many others who would love to try it, don’t know how to approach it. If you’re one of that group, this music improvisation article is for you. In this article, we’ll look at how music improvisation works and how you can do it just by understanding the basics of the music being played. Then you can apply the theory to practice and jam along with the 12-bar jam track in the video.

The Jam Track

The track in the video is a 12-bar progression ‘jam track’ played three times following a two-bar count in. The style of the jam track is generated by Band in a Box software. It’s described as “Bluegrass Rock – up-tempo even 8ths”. I’ve used it to create the 12 bar track that you can hear in the video. I’ve also added a very simple improvised guitar track in the first pass of the three ‘verses’ of the 12-bar and stuck it over in the far left stereo channel. It’s just to illustrate the points shown below about how to combine chord tones and non chord tones melodically in order to produce a shapely improvised part over the backing instruments. Depending on what you’re listening to the track on, you can filter out the added music improvisation by listening to the right stereo channel only and have the three verses all to yourself for improvising. Otherwise you’ll have to wait until the second verse if you want the stage to yourself.

Music Imrovisation | 12-bar Jam Track

The music backing track is in the key of A major, and it has been bluesified (if that’s a word) by adding ‘flat 7th’s to each chord. Technically, two of those (C & G)  put it out of key, but that’s what makes it sound bluesy. 

To play along with the track, what you have to be aware of is which chord is playing at any time, and what the chord tones of each chord are. In the video, you can see which chord is currently playing and which chord tones that chord is composed of.

Chord Tones

The first chord is A7. The notes (chord tones) of A7 are A, C#, E & G. That means if you improvise by playing any of those notes at any octave on any pitched instrument, they will never sound wrong. They can’t possibly sound wrong because all you’re doing is playing a note that’s already there, even if it’s at a different octave. The same applies to all the chords. Each chord has its set of chord tones and just by playing the chord tones of each chord (in any order you like) while that chord is playing, you’ll never hit a wrong note. 

That’s fine for harmonic improvisation. You’re just reinforcing individual notes of the chords, or even playing them in combination, such as strumming the chords on a guitar.

Adding non-chord tones

For melodic music improvisation, chord tones are essential, but on their own they’re not enough.  You need non-chord tones, too, to give the melody shape and directions. If you stick with just chord tones, you’ll fade into the background as you’re adding nothing new to the mix except maybe  some extra colour depending on what instrument you’re playing.

Non-chord tones are any notes that don’t belong to the chord currently being played. A chord tone in one chord may be a non-chord tone in the next chord. That’s why you should be aware of the chord tones of each chord. There are two types of non-chord tones: diatonic and chromatic.

Diatonic non-chord tones don’t belong to the chord but do belong to the key. The scale of the key shows the chord tones and diatonic non-chord tones arranged in pitch order.

As this jam track is in A major, the reference scale is: A B C# D E F# G#

The first chord, A7, has notes A, C# and E, and, as mentioned earlier, an out-of-key ‘bluesy’ note G.

So the remaining notes, B, D, F# and G# are diatonic non-chord tones. So how can they be used? 

Passing Tones

The most common use of non-chord tones in music improvisation is as passing notes between chord tones. Think of chord tones as safe havens and passing notes as stepping stones between them.  For example, while the chord is A7, you can have a melodic run using the notes A, B, C#, D, E. The B connects A to C# and the D connects C# to E. 

Auxiliary Tones (neighbour Tones)

Auxiliary tones are like passing notes that change their mind and return to the note they’ve just left. For example, a melodic phrase over the D7 chord could be D E F# G F#

D and F# are safe chord tones; E is a passing tone and G is an auxiliary or neighbour tone. If the melodic phrase had continued from G to A instead of of returning to F#, it would be a passing tone.

Accented non-chord tones

If you play a non-chord tone on a strong beat, such as the first note of a bar, it really stands out because, being a non-chord tone, it creates dissonance. Non-chord tones used as passing notes are also dissonant but coming between the beats, their dissonance is mush less noticeable. On a strong beat, though, everyone notices and the expectation is to hear the dissonance resolved by following up with the nearest chord tone. 

Chromatic Non-chord Tones

Chromatic non-chord tones not only don’t belong to the chord, they don’t even belong to the key. The most common use of them is as brief notes that move by semitone step (half step) to a chord tone. In the added improvisation guitar part, you can hear that the very first note is a a very brief non-chord tone, C, moving up a half step to the chord tone, C#. The last two notes in the 10th bar are similar. C, which is a chord tone of D7 but also out of key, drops to to the chord tone A of A7 in bar 11 – a very bluesy move, (but beware of clich├ęs).

Scale-based Music Improvisation

Many guitarists, especially rock guitarists, use a variety of scales as their note sources for melodic improvising. A usable scale is one that contains a good balance of chord tones and non-chord tones. The pentatonic minor scale, for example, is a very popular choice for improvising over a 12 bar blues and many rock progressions. The A pentatonic minor scale contains the notes A C D E G. Notice that two of the notes, C & G, are the two ‘out of key’ notes that are included in the chords of the jam track in this article.  Those are very bluesy-sounding notes, and, in fact, are referred to as blue notes. Pentatonic scales also have a unique sound as they have no semitones.

Scale-based Music Improvisation


 On the other hand, that scale (like most scales) is missing some important chord tones as well as important non-chord tones. The lesson to take from that is that you should never feel that you must stay within a particular scale at all times. In music improvisation, all notes are potentially usable notes, and you should never be limited by a set choice of notes. No experienced improviser would ever accept such a restriction. Music improvisation is all about creative freedom. Your ear and experience will eventually be the sole judge of what notes to use in any musical context.

Meanwhile start simple. Explore the chord tones, then bring in non-chord tones. Alternatively, choose a scale such as A pentatonic minor as a basis, but keep an eye on the chord tones, and be prepared to step outside of the scale whenever you feel it’s necessary. Listen to lots of great improvisers, and shamelessly steal their licks and runs; expand, modify and make them your own. That’s exactly what they did. 


All text, music and Images are by chasmac

“Bluegrass Rock uptempo even 8ths” Style (BGRock.sty) is by Band in a Box and is Copyright-Free.

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