How to make jazz music in your browser

By Tongkit Leong · September 23, 2026 · 9 min read

Jazz is built on extended chords, a swung rhythmic feel, and a walking bassline that outlines the harmony one note at a time — and you can program all three from scratch in the Tracks browser studio, with no software to install and no account to create.

What makes a track sound like jazz

Jazz draws on a different vocabulary than most popular genres, and a handful of ingredients do most of the work:

• Extended chords — sevenths, ninths, elevenths, and thirteenths instead of plain major and minor triads, which give the harmony its characteristic color and tension.
• Swing feel — eighth notes played unevenly, with the first note of each pair held slightly longer than the second, instead of the straight, even eighths used in most electronic and pop music.
• Walking bass — a bassline that moves in steady quarter notes, mostly stepwise, connecting one chord to the next rather than holding or repeating the root.
• Comping, not strumming — chords played as short, syncopated stabs with space between them, reacting to the soloist rather than filling every beat.
• Room for dynamics and phrasing — melodies and solos that breathe around the beat instead of locking rigidly to the grid.

Tracks has what you need for this already built in — a piano roll for writing chords and basslines by hand or by ear, swing and quantize controls for the groove, a drum machine for the ride and brushes, and a mixer with compression and reverb for gluing it together at the end.

Step 1: Set your tempo and turn on swing

Open the Tracks studio and set the BPM. Jazz covers a wide tempo range depending on the style:

• Ballad: under 80 BPM. Slow, spacious, built around long melodic phrases.
• Relaxed swing: 100–130 BPM. The classic mid-tempo jazz feel.
• Medium-up to up-tempo: 140–200+ BPM. Faster walking bass, denser comping, more energetic solos.

Once the tempo is set, turn on swing in the piano roll or step grid. Swing shifts every second eighth note later in its beat, so instead of two evenly spaced notes you get a long-short pattern. Try a swing amount around 55-65% as a starting point, and nudge it until the groove feels like it's leaning forward rather than sitting flat.

Step 2: Voice an extended chord progression

Add an instrument track, load a piano or electric piano sound, and open the piano roll. A dependable jazz starting point is a ii-V-I progression — for example Dm7, G7, and Cmaj7 in the key of C. Instead of stopping at plain triads, stack a seventh on top of each chord, and try adding a 9th on the ii and I chords or a 13th on the V chord for extra color.

Leave the root out of the upper voicing, or drop it an octave lower, since the bass track will cover it. This "rootless voicing" is a classic jazz piano technique and it makes the chord sound lighter and less cluttered than stacking every note in one register.

Comp with space instead of holding chords

Rather than sustaining each chord for a full bar, break the progression into short, syncopated stabs — a chord landing just before or just after a beat instead of squarely on it. Vary the rhythm from bar to bar so the comping reacts and breathes rather than repeating one fixed pattern. This is one of the biggest differences between a jazz comping part and a pop or rock chord part, and it's easy to hear once you try both back to back in the same piano roll clip.

Step 3: Write a walking bassline

Add a bass track and open the piano roll. Write one note per beat, mostly quarter notes, moving through the chord tones of whatever chord is currently playing — root, third, fifth, and seventh — plus the occasional passing tone that steps between them. On beat 4 of each bar, choose a note a half step or whole step away from the root of the next chord, so the line leads smoothly into the following change instead of jumping.

Keep the line mostly stepwise with an occasional small leap for interest, and let it move in one continuous direction across a bar rather than bouncing back and forth. A good walking bassline should feel like it could be sung from start to end.

Step 4: Program a swung ride and brushed drums

Open the drum machine and build a light, acoustic-feeling groove instead of a programmed electronic beat. Program a ride cymbal pattern with the swing feel from Step 1 carrying the pulse, a soft kick landing mostly on beat 1 with occasional light hits elsewhere, and a snare playing loose comping accents rather than a fixed backbeat on 2 and 4.

Keep velocities low and uneven across the pattern — jazz drumming leans on dynamic variation far more than a steady, quantized electronic groove does. If your kit includes brush or rimshot samples, layer those in on the snare for a softer, more acoustic texture than a standard snare hit.

Step 5: Add a melody or solo

On a saxophone, trumpet, or lead synth track, write the head melody in the piano roll by hand, following the chord tones and passing tones the same way you did for the bassline. For a more natural performance, connect a MIDI keyboard and record a solo live over the changes — playing a phrase by ear and correcting a few notes afterward almost always sounds more like jazz than programming every note on a rigid grid.

Let the melody phrase loosely around the beat rather than snapping every note to the grid. A phrase that starts a fraction late or lingers slightly on a note is part of what makes a jazz performance feel human instead of sequenced.

Step 6: Mix with headroom for dynamics

Jazz mixes rely on natural dynamics far more than most modern genres, so mix with a lighter touch than you would for something like house or trap:

1. Use light compression on the piano, bass, and lead so the performance's natural dynamics come through instead of getting flattened.
2. Add a short room or hall reverb across the mix bus at a low send level to glue the instruments together, as if they were recorded in the same room.
3. Balance the walking bass under the piano and drums so it's felt as much as heard, and check that the comping never buries the lead melody or solo.
4. Leave a few dB of headroom on the master fader instead of pushing it to full scale — jazz benefits from dynamic range rather than being squashed as loud as possible.

When the balance feels right, export to WAV for a clean master file or MP3 to share online — see How to export your song to MP3 or WAV for the full walkthrough. Your project stays in your browser the entire time; Tracks never uploads it anywhere.

Frequently asked questions

What chords should I use for a jazz progression?

Start with seventh chords instead of plain triads — major 7th, minor 7th, and dominant 7th are the core building blocks. A ii-V-I progression (for example Dm7, G7, Cmaj7) is the single most common jazz chord movement and a reliable place to start writing from.

How do I make my piano roll parts swing?

Turn on the swing control in the piano roll or step grid and set it somewhere around 55-65% as a starting point. Swing delays every second eighth note within its beat, turning even pairs of notes into a long-short feel. Apply it to the ride pattern and any comping or bassline part written in eighth notes for a consistent groove.

What makes a walking bassline different from a regular bassline?

A walking bassline moves in a steady stream of quarter notes, mostly stepwise, connecting one chord to the next rather than repeating or sustaining the root. It outlines the harmony continuously instead of just anchoring it, which is what gives jazz its sense of constant forward motion.

Can I record a real instrument for the melody instead of programming it?

Yes. Tracks supports microphone recording, so you can record a real saxophone, guitar, or vocal melody directly onto a track, or connect a MIDI keyboard over Web MIDI to play and record a piano or synth solo live. See How to record vocals in your browser for the recording setup, which works the same way for any mic input.