Studying jazz is hard. We all know that. Sometimes we make it harder for ourselves than it needs to be. I see a lot of horn players struggling with chord symbols and trying to generate some kind of line that matches them. I suspect that in some cases the learning style is not matched to the person. It might be useful here to look at the difference between your typical guitarist and your typical horn player learning jazz. Remember that these are generalisations and your mileage may vary.
Most student horn players that I meet read music well. And if you ask a horn player to play a particular scale, they probably can, or at least feel that they need to learn it. Most student guitar players that I meet are self-taught, and close to musically illiterate when they first arrive at jazz. And if they do have lessons, unless they learn classical guitar, most teachers won’t teach notation, but will focus on chords and technique. Many guitar players will panic if you ask them to play a scale or to read music and many will not know what notes are in a chord that they are playing. On the other hand, chord symbols are something familiar and it’s quite easy to learn to read them off a jazz chart. This gives guitar players (and pianists) a natural route from chord-symbol to chord to arpeggio, which makes it obvious how to improvise on chords. By the time they get to jazz they have an instinctive knowledge of harmony. For example, if you know how to play the chords to a reasonable number of pop tunes, you will have a good idea of the harmony that you’ll find in jazz standards, even if you don’t know the names of the chords.
Many horn players get lessons from the start, and I suspect that most teachers start with written music. Students learn associations between what they see (the dots) and the finger positions and mouth articulations that they need to make the appropriate sound. So you meet horn players who can sight-read semi-quavers at 200bpm but who are lost when chords come along. Horns don’t play chords (in the way that guitars or pianos do), so chords are not familiar.
What do people do when they see chords? A guitar player will play the chords, listen to how they sound, and pick out a line from the notes in the chords. It’s natural.
For many horn players the first instinct is that if you read melody from dots, you read chords from chord symbols. So the standard approach is – read the chords, try to remember which notes are associated with each chord symbol (also information gleaned from reading), and play them. Without any other input, the result will be something that is almost, but not quite, entirely unlike music. Even if the notes are correct (i.e. from a scale that matches the chord) I often feel that players don’t know what the notes mean. It sounds like someone trying to speak English with a guide book. You know, “My hovercraft is full of eels.” Perfectly good English, but signifying nothing.
Of course, there are people who find that the chord scale / arpeggio approach works well. If you don’t, here are some other things to try, that are intended to train your ears rather than your eyes. They may work for you or they may not. Recognise that this could take many years to get through. Many years of discovery and excitement.
Listen to the notes. Ask a nice guitarist or pianist to play the chords for you one at a time, and blow long single notes over the chords to see how they sound. (If you don’t have anyone to do this for you, use an app like Band-in-a-box or iRealB.) Maybe your instrument has 24 notes. Try all of them on each chord. Get the pianist or guitarist to vary their voicings and try them all again. Think about how each note makes you feel. Is it soothing or does it make you wince? Is it colourful or bland? Does it burn? Every note over a given chord has its own mood. Become intimately familiar with those moods.
Construct. Make up lines that put the colour tones in the important places, and see what they sound like. If they’re good, learn them. If they’re not good, tweak them until they are.
Transcribe. Write down your favourite solo from your favourite player. Maybe just do the juicy bits, you don’t need to do 10 choruses in one go. Also, don’t try to transcribe the really complex passages with flurries of 16th notes unless you find that easy. Find something simple. If you don’t have an idea where to start, try Chet Baker’s solo on It Could Happen To You from the album Chet Baker Sings.
Look at the use of colour in the playing (as well as phrasing, dynamics, swing and everything else). Learn to play what you have transcribed, slowly if necessary.
Don’t feel pressured to play lines of eighth-notes. Play what you learn at a speed that you can play well. Bird took Lester Young lines and played them in double time. You can take Bird lines and play them in half-time. Why not? Speed can come later. Better to play something slow that sounds nice than something fast that doesn’t.
This process informs your playing and also trains your ear. And if your reading skills aren’t great at the start, it will help there as well.
Play long notes. Make sure every note counts. Even in throw away phrases, each note should count. Any note that you play that isn’t as good as it could be is just obscuring the ones that are. The way to this is to play long notes. And fewer notes. Once you can play slow phrases that count, you can start to speed things up. Always keep an ear on the quality of the sound that you are making.
Learn arpeggios. With the extensions (9th, 11th, 13th) in all keys. Play them slowly, and not exclusively up and down, but in other orders. Make music with them. Play very slowly over the chords of tunes. Experiment with what happens when you alter the extensions.
Learn scales. Don’t learn them as a line of notes up and down the scale, make little musical phrases with scale notes. Play them slowly. Savour each note. Play them rhythmically, as music. Learn them all over your instrument. Get to know the mood of each mode of each scale, and the personality of each note in each mode. This is a big project but intensely rewarding.
Learn harmony. Even if it comes later. Harmony is a theoretical summary of what the other steps will teach you. The main advantage of knowing harmony is filling in the gaps in your knowledge, finding stuff that you haven’t thought of. If you can’t get your brain around harmony, don’t worry, save it for later, or for never. But don’t attempt to play harmony that you don’t understand. It’s always better just to listen and then play.