16-Step Drum Pattern Builder
Most beginner grooves die in the same place: the pattern is correct but it is dead. Quantised to the grid with every hit at the same velocity, a four-on-the-floor kick stops breathing and the track has nothing to say. This builder gives you a 4-by-16 grid you can click, a swing value measured in real milliseconds, and a set of feel numbers that tell you whether the groove you just drew is straight, swung or broken. Type or click kick, snare, hat and percussion as plain text, where x is a hit and g is a ghost note, and the tool counts the events, measures how much of the bar is filled, converts your swing percentage into the actual offset in milliseconds at your tempo, and estimates how often a producer would drop a fill into a phrase. Copy the result as four lines of text and paste it straight into your DAW or sampler.
How to use it
Set the tempo before anything else. A 16th note at 128 BPM is 117.2 ms long, at 140 BPM it drops to 107.1 ms, so the same swing percentage produces a different groove once the tempo moves. The tool converts your swing into milliseconds for you, because that is the number you can feel.
Pick a style reference. House, techno, drum and bass and trap each carry their own base fill rate and their own classic 16-step skeleton, which the tool shows next to your pattern so you can see how many events you added or left out. Choose Custom when you do not want any reference at all.
Build the grid by clicking cells or by typing. Clicking cycles a slot through empty, hit and ghost note. Typing is faster for structured patterns: x for a hit, g for a ghost note, a dot for silence, exactly 16 characters per row for kick, snare, hat and percussion.
Read the feel numbers, then copy the pattern. Density tells you how busy the bar is, the swing delay tells you how far the offbeats are pushed, the fill probability tells you how often a producer would break the loop, and the four lines under Copy the pattern drop straight into your DAW.
Three common mistakes
- Treating swing as a percentage of the bar instead of a percentage of one 16th note. Swing 12 percent at 128 BPM means the offbeat 16th lands 14.1 ms late, not 12 percent of the bar. Get this wrong and the number becomes meaningless, because the same setting feels completely different at 90 BPM and at 140 BPM.
- Counting every ghost note as a full hit. A ghost snare is the same sample at roughly 40 percent velocity, so it adds almost no level but it does add density and it does make the groove feel looser. The tool counts ghosts separately for exactly this reason, and the fill rate moves when a track changes between the two halves of the bar.
- Expecting the grid to contain the fill. A 16-step loop with no fill will still score a healthy fill probability, because the number describes how likely a producer is to add one, not how many fills are already in the loop. Write the fill as a variation of the last bar and keep the count of events in mind.
- Reading grid density as loudness. 15 percent density at 128 BPM means 10 events per bar, which is a normal house groove, but those events could be a soft rimshot or a distorted kick. Density tells you how full the bar is, never how heavy it sounds.
How the feel numbers are actually calculated
Every number on this page comes out of the four rows you typed, so it is worth knowing what each one means before you start tuning.
- Grid density is note events divided by the 64 sixteenth-note slots in one bar. Your default groove gives 10 events, so 15.6 percent. A busy trap pattern sits above 25 percent, a minimal ambient groove sits under 8 percent.
- Swing delay converts your percentage into time: the 16th-note length is 60000 divided by BPM divided by 4, and your swing percentage is applied to that. At 128 BPM a 16th is 117.2 ms, so 12 percent swing is 14.1 ms of push on every offbeat 16th. The triplet feel lives near 33 percent, which is 39.1 ms here.
- Fill probability starts from a base rate for the chosen style, then adds 7 points for every track whose second half differs from its first half. A snare that plays differently in beats 3 and 4 is the classic sign that somebody is about to write a fill.
- Feel is a three step ladder: under 8 percent swing is straight, 8 to 40 percent is swung, and anything above 40 percent swing, or four or more ghost notes, is called broken because the pocket stops being regular.
None of these are taste judgements. They are descriptions of what you drew, so you can compare two versions of a groove and see exactly what changed.
Ghost notes, velocity and the 40 percent trick
The difference between a loop that sounds programmed and a loop that sounds played is usually velocity, not timing. A ghost note is a normal drum hit played far softer, usually at 35 to 45 percent velocity, and it is what puts a snare just ahead of the main backbeat or a kick just before a fill. That is why the pattern language here uses a third character, g, instead of only x and a dot.
Two rules keep ghost notes useful. First, a ghost should be a note you can afford to lose. If the groove still works when the ghost is muted, the ghost is doing its job: it adds push without carrying information. Second, a ghost should never land on the same step as a full hit on the same voice, because that is not a ghost, that is a flam, and flams need intent.
When you move a pattern from this grid into a DAW, do not rebuild it from scratch. Paste the text pattern into the step list, then go through the g characters and set those velocities to 40 percent while leaving the x characters at 100. If your drum library has dedicated ghost samples, load those instead of reaching for the velocity fader, since a dedicated ghost sample usually has a softer transient and a shorter decay that reads better in a busy mix.
Watch the level. Ghost notes add density without adding much level, which is exactly what you want, but a dense pattern with many ghosts can still push a bus into the compressor earlier than you expect. Keep an eye on the density number here and on the headroom in the mix bus.
From pattern text to a real session
The four lines this page exports are deliberately dull: one letter per sixteenth-note slot, read left to right. That is the format every step sequencer understands and every producer can read at a glance in a chat window, so it survives the trip from a web page to a hardware drum machine without a translation layer.
A sensible session order looks like this. Write the kick first and confirm the grid at 1x speed, because a kick that drifts is a kick that ruins the mix. Add the snare on the backbeat, then add the ghost note and check that it sits slightly ahead of the main hit. Add hats last, because they are the part you will move most once the rest of the track exists. Only then apply swing, and only to the hats if the kick and snare already feel right.
Keep the pattern looped for the length of a phrase rather than a single bar. A single bar loop is the single most common reason a beat feels like a tutorial, since every four bars the producer resets to exactly the same moment and the listener notices. Where you want tension, copy the last bar of an 8-bar phrase and change one or two characters, often a snare into a ghost or a hat into a tom, and that single change is what the fill probability on this page is trying to quantify.
Finally, treat the numbers here as a starting point for listening. The tool can tell you that a groove carries 10 events per bar and 25 percent fill probability, and it can tell you the offbeats sit 14.1 ms behind the grid. It cannot tell you whether the result makes you move. Put the numbers in front of you, then move the fader.
FAQ
What exactly does the swing percentage mean, and how do I convert it into milliseconds?
Should a ghost note count as one of my hits?
Is 15 percent grid density too busy for a house track?
Why does this tool not tell me whether my pattern sounds good?
How do I get this pattern into Ableton, FL Studio, Logic or a hardware sampler?
Limits of this tool
- The swing delay assumes a hard grid at a constant tempo. Recorded material with any timing drift will not line up with these numbers, and the tool cannot measure drift from a text pattern.
- The fill probability is a writing heuristic built on style base rates, not a measurement of an existing track. Use it to compare your own patterns against each other.
- The main limitation of any pattern grid is that it shows where hits land, never how loud or how bright they are. Velocity, sample choice and processing change the groove more than the timing does.
- Ghost notes are written as g and assumed to sit at roughly 40 percent velocity. If your drum library ships separate ghost samples, load those instead of lowering a velocity fader.