Most guitarists learning jazz hit the same wall: they’ve memorised the scales and arpeggios, but their playing doesn’t sound like jazz. The gap between knowing what to play and actually sounding good is enormous — and in this masterclass, Danish jazz guitarist Jens Larsen walks you through a practical, language-based approach to closing it.
What you’ll get out of this lesson: A clearer way to think about jazz improvisation — one rooted in melody and vocabulary rather than pattern memorisation. You’ll understand why one-octave diatonic arpeggios are the cornerstone of authentic jazz phrasing, and you’ll have a concrete exercise to start building that vocabulary today.
Jazz is a language, not a scale system
Jens makes an important distinction right at the start: there is a difference between teaching people what to play and teaching them how to make it sound good. Knowing the altered scale or a half-diminished arpeggio is only the beginning. As he puts it, blues has a certain sound — and you can take a pentatonic scale and play something that sounds nothing like blues at all. Jazz is exactly the same. The notes are a starting point, not the destination. The goal is to develop a fluent musical language.
Why one-octave arpeggios are the key
One of the central ideas Jens shares is the importance of practising arpeggios as one-octave melodies rather than full-position shapes. When you listen to jazz — and Jens is clear that listening is the only real way in — you notice that players almost always use one-octave arpeggio fragments, not sweeping multi-octave patterns. Practising them this way gives you building blocks: four-note phrases that sit naturally inside your lines and fit directly into what you need in a solo.
Crucially, playing arpeggios within a scale connects them to the surrounding harmony. Because jazz is largely tonal music, the scale often stays the same while the chord changes — and having your arpeggios rooted in that scale means everything ties together organically.
The diatonic arpeggio exercise
The core exercise Jens recommends starts with a C major scale at the eighth fret and involves playing the diatonic seventh-chord arpeggios for every degree of the scale: C major 7, D minor 7, E minor 7, F major 7, G7, A minor 7, B half-diminished, and back to C major. Each one is played as a one-octave melody. This builds two things simultaneously: a technical overview of the harmony in the key, and a repertoire of melodic building blocks that are already close to how you’d use them in a real solo.
The deeper benefit is that once you have these diatonic arpeggios under your fingers, you also have the raw material for using multiple arpeggios over a single chord — a key tool in advanced jazz vocabulary.
Connecting arpeggios to lines
Jens draws on the teaching of Barry Harris when discussing how to move from isolated arpeggios to actual improvised lines. The step is to take an arpeggio and connect it to the surrounding scale material — playing it as part of a phrase rather than as a separate shape dropped into the music. A common mistake he’s seen in students (and experienced himself) is treating arpeggios as patterns that exist outside the scale. When you practise them within the scale context from the start, they become part of a continuous melodic thought rather than an interruption.
If you want to play in a certain way, you need to practise things that are really close to how you want to sound. That’s what’s going to help you play better. That’s essentially what the goal is.
Taking it further: Once you’re comfortable with the diatonic arpeggio exercise in C major, take it through other keys and positions. Then explore using more than one arpeggio over the same chord — for example, over C major 7, try both the C major 7 arpeggio and the E minor 7 arpeggio (the third-degree diatonic arpeggio) and notice how the sound shifts. Jens also mentions that listening to jazz — really listening — is just as essential as any technical exercise. Put on recordings alongside your practise sessions.
Your homework: Take the C major scale at the eighth fret and play through all seven diatonic seventh-chord arpeggios as one-octave melodies — ascending and descending each one before moving to the next. Do this slowly and evenly, keeping each arpeggio clearly rooted in the scale. Spend at least 15 minutes on this daily for the next week, and then try the same exercise starting from a G major scale.