Further technical hurdles

‘I do this not because it is easy, but because I thought it would be easy.’ It seems like there’s still a lot to do before I can actually start recording. The legacy of the scorewriting workflow I got used to now comes back at me. So I need to learn new tools, adapt to new formats, and find a new workflow. However, I can do this because I want to do this. And one thing I know is: Going the hard way leads to many insights.

Scoring with a drum machine

In my last blog post I wrote about how I got used to save my ideas with a tablature editor and happened to compose and arrange with it. But that’s only half the story. Since the drums of a soundfont quickly sounded not vivid enough for me and I was curious to try out other free software, I started scoring drums with Hydrogen, the advanced drum machine.

Using the integrated Sound Library¹ the drumkit Flac_GSCW-2, which is based on samples from Salvador Pelaez², appealed to me. Hydrogen provides a lot of options to fine tune the sound of a drumkit. However, I have basically used it to better imagine the sound of the drums in my arrangements. And I ended up drictly feeding single instrument tracks, such as the kick, snare, etc., into separate tracks in Ardour in the recording step to do the fine tuning in the DAW bypassing all the advanced options of Hydrogen.

Exporting a Hydrogen Song to MIDI

My drums scores are currently saved in Hydrogen’s XML³ format and bound to the drumkits provided by Hydrogen. In order to work with the Tchimera Drum Kit, as described in the #Drums section of my pro audio documentation, I export the Hydrogen song (.h2song) to MIDI.

However, importing the resulting .mid file into an Ardour MIDI track—which has been initialized with an sfizz-multi instance loading the full_kit.sfz of the Tchimera Drum Kit virtual instrument—doesn’t do the magic. While listening to the MIDI notes triggering the samples in sfizz I note that a crash cymbal is triggered instead of a low or floor tom, for example.

The reason is that the mapping of MIDI notes for the Flac-GSCW-2 drumkit in Hydrogen is different to the mapping of the Tchimera Drum Kit provided as SFZ file. The value in the Note field of the MIDI Output control bar on the lower right side of the image above reveals that the Snare instrument is mapped to note 37, for example.

Flac_GSWC-2 default mapping

First, I write down the notes used in the Hydrogen drumkit Flac_GSCW-2. The following table shows the mappings and the General MIDI (GM) standard for reference:

Note	GM4	Flac_GSCW-2
36	Electric Bass Drum	Kick
37	Side Stick	Snare
38	Acoustic Snare	Snare flam
39	Hand Clap	Snare side stick
40	Electric Snare or Rimshot	Snare roll
41	Low Floor Tom	Snare rim shot
42	Closed Hi-hat	Snare drag
43	High Floor Tom	Crash 14"
44	Pedal Hi-hat	Crash 14" choke
45	Low Tom	Crash 18"
46	Open Hi-hat	Crash 18" choke
47	Low-Mid Tom	Tom 13"
48	High-Mid Tom	Tom 12"
49	Crash-Cymbal 1	Ride 22" - bell
50	High Tom	Tom 10"
51	Ride Cymbal 1	Ride 22"
52	Chinese Cymbal	HH closed
53	Ride Bell	Tom 12" flam
54	Tambourine	HH open
55	Splash Cymbal	Tom 10" flam
56	Cowbell	HH pedal
57	Crash Cymbal 2	Tom 13" flam
58	Vibraslap	Splash 6"

At first glance, this mapping appears to have been made in sequence accounting for instruments to be triggered on notes you wouldn’t expect, if you are already familiar with the GM standard.

Tchimera Drum Kit default mapping

Next, I investigate the keymap.sfz file containing the mapping of the Tchimera Drum Kit as shown in this table:

Note	GM and GS5	Tchimera Drum Kit
22		HIHAT_CLOSED_EDGE
23		HIHAT_HALF_BOW
24		HIHAT_HALF_EDGE
26	Finger Snap (GS)	HIHAT_OPEN_EDGE
30	Scratch Pull (GS)	TRASH_BOW
31	Sticks (GS)	TOM_4
32	Square Click (GS)	TRASH_EDGE
33	Metronome Click (GS)	TOM_4_RIM
35	Acoustic Bass Drum	KICK_FREE
36	Electric Bass Drum	KICK_DAMP
38	Acoustic Snare	SNARE_CENTER
39	Hand Clap	SNARE_EDGE
40	Electric Snare or Rimshot	SNARE_RIM
41	Low Floor Tom	TOM_3
42	Closed Hi-hat	HIHAT_CLOSED_BOW
43	High Floor Tom	TOM_3_RIM
44	Pedal Hi-hat	HIHAT_PEDAL
45	Low Tom	TOM_2
46	Open Hi-hat	HIHAT_OPEN_BOW
47	Low-Mid Tom	TOM_2_RIM
48	High-Mid Tom	TOM_1
49	Crash-Cymbal 1	CRASH_1_BOW
50	High Tom	TOM_1_RIM
51	Ride Cymbal 1	RIDE_BOW
52	Chinese Cymbal	CRASH_2_EDGE
53	Ride Bell	RIDE_BELL
55	Splash Cymbal	CRASH_1_EDGE
57	Crash Cymbal 2	CRASH_2_BOW
58	Vibraslap	RIDE_EDGE

In addition to General MIDI, the mapping expands down to note 22 including notes that are part of the General Sound or General Standard (GS) superset and even non-percussion notes (notes below 26). And compared to GM and GS the mapping in the Tchimera Drum Kit appears to be rather less systematic. The reason is that the notes correspond to those used in typical e-drums hardware made by Alesis, Roland, and Simmons.

E-drums often provide different trigger zones to simulate different sounds produced by hitting a drum or cymbal at the bow or edge, for example. For this reason, there are six mappings for hihat sounds and three mappings for the snare. Though this doesn’t comply with the GM and GS standards it’s a good practice to not spread the notes across the whole spectrum.

Remapping in Hydrogen

The tables reveal that Flac_GSCW-2 and Tchimera Drum Kit are different drumkits providing different samples using different MIDI notes and a one-to-one match isn’t possible. However, to generate a MIDI export that triggers most of the instruments just fine (kick, snare, hihat, toms, cymbals), I can remap the notes used in Hydrogen to similar instruments of the Tchimera Drum Kit before exporting the song:

Note	GM and GS	Tchimera Drum Kit	Flac_GSCW-2
22		HIHAT_CLOSED_EDGE	HH closed
26	Finger Snap (GS)	HIHAT_OPEN_EDGE	HH open
36	Electric Bass Drum	KICK_DAMP	Kick
38	Acoustic Snare	SNARE_CENTER	Snare
40	Electric Snare or Rimshot	SNARE_RIM	Snare rim shot
41	Low Floor Tom	TOM_3	Tom 13"
44	Pedal Hi-hat	HIHAT_PEDAL	HH pedal
45	Low Tom	TOM_2	Tom 12"
48	High-Mid Tom	TOM_1	Tom 10"
51	Ride Cymbal 1	RIDE_BOW	Ride 22"
52	Chinese Cymbal	CRASH_2_EDGE	Crash 18"
53	Ride Bell	RIDE_BELL	Ride 22" - bell
55	Splash Cymbal	CRASH_1_EDGE	Crash 14"

Additional instruments in Hydrogen, such as Snare flam, Snare roll, Crash 14" choke, Splash 6" etc., are mapped to a range of notes unused in the Tchimera Drum Kit (60 to 69):

Note	GM	Flac_GSCW-2
60	Low Bongo	Snare flam
61	High Bongo	Snare side stick
62	Mute High Conga	Snare roll
63	Open High Conga	Snare drag
64	Low Conga	Crash 14" choke
65	High Timbale	Crash 18" choke
66	Low Timbale	Tom 10" flam
68	Low Agogô	Tom 12" flam
67	High Agogô	Tom 13" flam
69	Cabasa	Splash 6"

Motivation

This way I can maintain the note information (length, timing, velocity etc.) and decide to drag the note to another note for triggering another instrument while working with MIDI in Ardour or find other ways to produce the sound I intended. The additional instruments cannot occupy the same note as the regular Snare, for example. Otherwise, they would be discarded as a duplicate note on export.

Although it will take some time to get used to the features of the Tchimera Drum Kit and a lot of work will be required to find ways to maintain the intended sound of the drums I composed using Flac-GSCW-2 in Hydrogen, I am confident that I can tackle Dozen Lessons for Educationists well, soon.