You drag a drum groove into your DAW, press play, and the snare comes out as a hi-hat, the crashes are toms and the kick is fine. Nothing is broken. The groove and your drum VST just disagree about which note means which drum.

This post explains what a drum map is, why maps disagree, and three ways to fix it for good. There is also a two-minute test to run whenever you load a new groove or a new drum VST.

In this post:

• What MIDI actually sends
• General MIDI: the shared map
• Why your VST plays the wrong drum
• Three ways to fix it
• A two-minute test
• Questions

What MIDI actually sends

A MIDI file has no sound in it. For each hit it stores three things: which note (a number from 0 to 127), how hard (the velocity, 1 to 127) and when. Your drum VST decides which sample to play for each note number. That list, note number to drum, is its map.

So the same MIDI note 42 is a closed hi-hat in one VST and, in another, a completely different drum. The MIDI never changed; the map did.

General MIDI: the shared map

General MIDI (GM) is the standard most drum MIDI is written to. It puts each drum on a fixed note. These are the ones you meet in metal:

Note	General MIDI drum	Note	General MIDI drum
35	Acoustic bass drum	46	Open hi-hat
36	Bass drum (kick)	47	Low-mid tom
37	Side stick	48	High-mid tom
38	Acoustic snare	49	Crash cymbal 1
40	Electric snare	50	High tom
41	Low floor tom	51	Ride cymbal 1
42	Closed hi-hat	52	Chinese cymbal
43	High floor tom	53	Ride bell
44	Pedal hi-hat	55	Splash cymbal
45	Low tom	57	Crash cymbal 2

We read 32 grooves from 8 of our packs to see which notes they actually use. All of them are on the General MIDI map: 12 notes in all.

Why your VST plays the wrong drum

Almost every drum VST agrees on the kick (36) and snare (38). The trouble starts with everything else.

• Hi-hats. A modern VST has many hi-hat sounds: closed, tip, edge, several stages of open, pedal, splash. They do not fit on the three GM notes, so each VST spreads them across the keyboard its own way.
• Cymbals. Several crashes, a china, a splash, a ride with bow, edge and bell, and chokes for each. Again, more sounds than GM has notes.
• Toms. GM has six tom notes; a kit may have three, four or five toms, and VSTs order them differently.
• Two different maps in one VST. Many VSTs load their own map by default and offer General MIDI as an option you have to choose.

Note names add a second problem

Your DAW shows notes as names like C1 or D#2. But DAWs do not agree which octave is which: depending on the DAW, note 60 is called C3, C4 or even C5. So note 36, the kick, can appear as C1, C2 or C3. When a guide or a VST manual says “kick on C1”, go by the note number, not the name. Our drum map lists every note by number, with the name in both common conventions.

Three ways to fix it

1. Switch the VST to General MIDI (best)

Look in your drum VST’s MIDI or mapping settings for a map called General MIDI, GM, or similar. Load it, and GM grooves play the right drums. This fixes every groove at once, and it is the fix to try first.

2. Remap in the DAW

Most DAWs can translate notes on the way into an instrument: a drum map, a note-remapping MIDI effect, or a drum instrument where you choose which note each pad listens to. Set it up once, save it as a template, and every groove you drop onto that track is translated.

3. Move the notes themselves

In the piano roll, select every note in one lane (for example every 42) and drag it to the note your VST uses for that drum. It is quick for one groove and tedious for twenty, so use it for one-offs.

Tip: fix the map on the instrument track, not in each MIDI clip. Then any groove you drop onto that track plays the right drums, and you never have to fix it again.

A two-minute test

Load one groove, loop two bars, and check each lane in turn. Here is a heavy verse from Metalcore Essentials: every lane is one MIDI note, labelled with its number.

Lane	Note	You should hear	If you hear something else
Kick	36	Kick drum	Rare; check the VST is on the right MIDI channel
Snare	38	Snare, centre hits	Map not on GM
Hi-hat	42 / 46	Closed and open hi-hat	The most common mismatch; switch to GM
Toms	43, 45, 47	Floor tom, low tom, mid tom	Tom order differs; remap
Cymbals	49, 57, 51, 53, 52	Crash, second crash, ride, ride bell, china	Remap or pick the GM map

If every lane is right, save the setup as a track template. If one lane is wrong, fix that note only, with the second or third method above.

Questions

Do Whack Studio packs work with EZdrummer, Superior Drummer, GetGood Drums or Steven Slate Drums?

Yes. The packs use General MIDI notes, and these VSTs can play GM grooves (some need their GM map chosen first). Each pack also includes a text file listing the note for every drum.

What is the difference between note 35 and note 36?

Both are kick drums in General MIDI (35 is “acoustic bass drum”, 36 “bass drum 1”). Most drum VSTs put their main kick on 36, and that is the kick the packs use.

Why is my hi-hat always open, or always closed?

Either the map sends 42 and 46 to the wrong sounds, or the VST sets how open the hi-hat is with a pedal controller (MIDI CC 4) and is waiting for that controller. Check the VST’s hi-hat settings, and try its General MIDI map.

My groove plays the right drums but sounds weak. Is that the map too?

Usually it is velocity. Check your VST’s velocity response and make sure quieter notes are not being pushed down to its softest samples. Our grooves use velocities from about 40 for ghost notes up to 127.

Once the map is right, every groove in The Everything Bundle drops straight onto the track: 21 packs of played metal drum MIDI, all on the same General MIDI notes.