Drum MIDI Pattern Editor

How Drum MIDI Pattern Editors Work: General MIDI, Step Sequencers, and DAW Workflow

The MIDI standard, ratified in 1983, has never been revised at its core. Every drum machine, sequencer, and DAW in the world today still speaks the same protocol that Roland, Korg, and Sequential Circuits agreed on over four decades ago. One consequence of that longevity is that drum programming has a completely defined address space: channel 10 in 1-indexed numbering (or channel 9 in 0-indexed) is permanently reserved for percussion, and each note number from 35 to 81 maps to a specific drum sound under the General MIDI specification. Your kick drum is always MIDI note 36. Your snare is always note 38. That consistency is what makes it possible for a pattern you program here to open correctly in Ableton Live, FL Studio, Logic Pro, Reason, or any other compliant host, without any reconfiguration.

How a Step Sequencer Grid Translates to MIDI

A step sequencer divides one bar (or a fixed number of bars) into equal-length slots called steps. The most common grid is 16 steps in 4/4 time, where each step represents one sixteenth note. At 120 BPM, a sixteenth note lasts exactly 125 milliseconds. When you activate a cell in the grid for the kick drum on step 1 and step 9 (the "1" and the "3" of the bar), you are telling the sequencer: fire MIDI note 36 at time 0 seconds and again at time 0.5 seconds.

When you export that pattern as a MIDI file, the editor writes a Standard MIDI File (SMF). An SMF stores musical data as delta-time events: each event records how many MIDI ticks have elapsed since the previous event. At a resolution of 480 ticks per quarter note (the most common setting), a sixteenth note is 120 ticks. The file header stores the tempo as microseconds per beat. At 120 BPM that value is 500,000 microseconds. Any sequencer that receives this file can reconstruct exactly the same rhythmic relationships regardless of how it handles playback timing internally.

General MIDI Drum Note Mapping and Why It Matters

The General MIDI Level 1 specification, published by the MIDI Manufacturers Association in 1991, standardized 47 percussion sounds on channel 10. The mapping used in this editor matches those definitions exactly:

• Note 36 (C2): Bass Drum 1 (kick)
• Note 37 (C#2): Side Stick (rim shot)
• Note 38 (D2): Acoustic Snare
• Note 39 (D#2): Hand Clap
• Note 42 (F#2): Closed Hi-Hat
• Note 43 (G2): High Floor Tom
• Note 46 (A#2): Open Hi-Hat
• Note 47 (B2): Low-Mid Tom
• Note 49 (C#3): Crash Cymbal 1
• Note 50 (D3): High Tom
• Note 51 (D#3): Ride Cymbal 1

When you drop the exported MIDI file onto a drum rack in Ableton Live, a Beat Creator in Logic, or a Step Sequencer in FL Studio, the host maps these note numbers to the correct sample slots automatically, because every GM-compliant drum instrument uses the same mapping. If you are using a non-GM instrument (a custom drum rack with samples loaded manually, for example), you may need to reassign the note numbers to match your kit layout. In that case, the note numbers in the exported file give you a clear reference for where to map each sound.

Velocity, Dynamics, and Why Flat Patterns Sound Mechanical

Velocity in MIDI is a number from 1 to 127 that represents how hard the drummer hit the drum. In practice, a velocity of 127 is a very hard accent. A velocity of 64 is a medium hit. A velocity around 30 to 40 is a ghost note, the kind of quiet snare hit that fills the space between the main backbeat and gives funk and jazz patterns their texture.

Patterns where every step has the same velocity (often 100 or 127 by default) sound robotic. Real drummers play with constant velocity variation. A standard 4/4 rock pattern has the kick and snare at 100 to 110, the hi-hats on beats 1 and 3 at around 85, and the hi-hats on the "and" subdivisions at 60 to 70. The difference in loudness creates the perception of forward motion and groove. To adjust velocity per step in this editor, right-click any active cell to open the velocity slider for that step. You can also use shift-click to set a step directly to accent velocity (around 115 to 120) for a quick way to mark the strong beats.

The Rhythm Pattern Generator on this site handles randomization and playback without MIDI export. This editor is the companion tool when you need to take patterns into a DAW for production. Once you have a groove you like here, export it, drop it into your session, and layer it with your actual drum samples or virtual instruments.

Swing: What It Is and How to Use It

Swing, also called shuffle or groove, shifts the timing of even-numbered sixteenth notes (the "and" subdivisions) slightly later than their mathematically exact position. At 0% swing, all 16 steps in a bar are spaced exactly 125 ms apart at 120 BPM. At 66% swing (the maximum triplet swing, also called "full triplet feel"), the even steps land on the last third of each eighth-note pair, giving the pattern a triplet-like lilt. Most practical swing values for modern music fall between 15% and 40%.

Jazz drummers typically play with much more swing (50% to 65%) than hip-hop producers (15% to 25%). The MPC-style "swing" in classic hip-hop was a specific implementation: the MPC60 and MPC3000 shifted every other sixteenth note by a fixed percentage, and values around 54% to 58% became associated with the J Dilla and Pete Rock era sound. The swing control in this editor applies the same principle: odd-numbered steps (steps 2, 4, 6, etc. in 0-indexed counting) are delayed by a percentage of the step duration. The exported MIDI file encodes this timing shift as modified delta-time values, so the swing is baked into the file and plays back correctly in any host.

Importing Existing MIDI Files

The import feature reads any standard MIDI file that contains notes on channel 9 (GM drum channel). The importer quantizes note timings to the nearest sixteenth note in the current step grid, maps each note number to the correct track row using the GM table, and populates the grid with the detected pattern from the first bar of the file. This is useful when you have a reference drum loop from a sample pack MIDI library and want to edit it step by step, or when you want to analyze what steps a specific genre pattern uses before building your own variation.

If the MIDI file uses a non-standard or custom drum map rather than GM channel 9, the importer will not find any notes. In that case, you can still use the MIDI to Sheet Music tool to visualize the file contents and identify the note numbers manually before re-programming the pattern.

Exporting to Ableton Live, FL Studio, and Logic Pro

The exported file is a Type 0 (single-track) Standard MIDI File. All DAWs accept Type 0 files, though they handle them differently:

• Ableton Live: Drag the .mid file onto an empty MIDI track that has a drum rack loaded. Ableton will ask whether to import as a clip, and the notes will populate the drum rack pads according to the GM note mapping. If you use a drum rack with custom samples not mapped to GM, you will need to reassign the notes.
• FL Studio: Open the MIDI file with File > Import MIDI. FL Studio's FPC pattern or a Step Sequencer instance can receive the data. Alternatively, drag the file into the Playlist to create a MIDI clip on an instrument channel.
• Logic Pro: Import via File > Import > MIDI File, or drag it directly into the arrangement area. Logic will create a new Software Instrument track with the drum MIDI data. Assign the track to Drummer (set to MIDI mode) or any third-party drum plugin.
• GarageBand: Drag the .mid file into the GarageBand tracks area. GarageBand will create a new MIDI region that you can edit in the Piano Roll or assign to a drum software instrument.

The MIDI Manufacturers Association publishes the full GM Level 1 specification at midi.org, which documents the complete drum map alongside the melodic instrument list. It is the authoritative reference for note number assignments if you are mapping to a custom instrument that deviates from the defaults.

Programming Effective Drum Patterns by Genre

Genre presets in this editor give you a starting point, but understanding the underlying structure helps you deviate from the template intentionally:

Rock (4/4, 16 steps): Kick on steps 1 and 9, snare on steps 5 and 13, hi-hats on every even step. Accenting the snare at velocity 100 to 110 while running hi-hats at 70 to 80 is the foundation of nearly every rock record from Led Zeppelin to modern stadium pop.

Hip-Hop (4/4, 16 steps): The kick typically lands on step 1 and somewhere unexpected in the second half of the bar (step 11 or 12 for the "trap lean"). Snare on steps 5 and 13. Closed hi-hats running as sixteenths at low velocity with occasional open hi-hat on step 8 or 16 for the "swish." Apply 20% to 30% swing for authentic feel.

Funk (4/4, 16 steps): The kick is syncopated and rarely sits only on beats 1 and 3. Ghost notes on the snare (velocity 30 to 45) between the main backbeats are what makes a funk pattern breathe. Listen to James Brown's "Funky Drummer" by Clyde Stubblefield: the ghost notes on the snare carry as much rhythmic information as the backbeat itself.

Jazz (6/8 or 4/4 with heavy swing): The ride cymbal carries the main pulse, usually on the quarter notes or in a "spang-spang-a-lang" triplet pattern. The hi-hat foot closes on beats 2 and 4. The snare and kick are loose and reactive rather than on a fixed grid. Jazz patterns programmed into a step sequencer always sound somewhat mechanical because the art of jazz drumming is precisely the variation that falls outside the grid.

Using the Pattern Editor in Your Production Workflow

A practical workflow: use this editor to sketch 4 to 6 contrasting patterns (verse groove, chorus groove, fill, breakdown, outro). Export each as a separate MIDI file. In your DAW, create one drum instrument track and drag all the MIDI clips onto it. Arrange the clips in the timeline to match your song structure. This gives you full control over the arrangement without having to program everything inside the DAW's own MIDI editor from scratch.

If you are building a complete song structure before touching sound design, the Song Structure Builder is a useful companion for mapping out how many bars each section needs. Combined with the BPM Tap Tool for locking in tempo from a reference track, these tools cover the core planning phase before you enter the DAW.

For producers who want to go deeper into MIDI file analysis after programming patterns, the MIDI to Sheet Music converter lets you view the exported file as standard notation, which can surface rhythmic relationships that are less obvious in a step grid. Velocity information shows up as note dynamics, making it easier to spot where your ghost notes are and whether your accent structure is reading the way you intended.