How To Create Drum Loops That Sound Acoustic

I don't quite remember when I made my first loop. I think it was for some long forgotten horror film in the mid-to-late '80s. It may still be around on a 3.5" floppy in a dusty case, but I digress. We're here to discuss ways to create acoustic-sounding drum loops, but keep in mind that this is only how I create them. Your methods will be determined by the hardware and software you have, and the style of music in which the loops will be used.

Much of today's popular music uses drum loops. It might be a loop a composer uses as inspiration while writing a song or a loop used in the final production. Either way, loop "content creation" has become a way to earn a living, and another part of what we are expected to do as working drummers. If you're looking for a new profit source, it can pay to spend some time behind the computer working on your mouse chops.

Creating loops is not that complicated. It's important to listen to a lot of music that uses loops, which is almost every kind of popular music out there these days. This will help you develop an ear for how loops are used, and the kind of sounds that are currently in vogue. At times, it's hard to distinguish what combination of sounds you hear. You might hear a loop, programmed drums, electronic drums, acoustic drums, or some combination of all the above. But have faith. Eventually you'll develop the ability to dissect all the different parts. If you have friends or acquaintances that are currently using loops in their live or recorded music, pick their brains, hang out, and learn as much as you can. Practical, "real life" experience is priceless.

One of your keys to success is to know the tools at your disposal. This means in addition to keeping up your subscription to DRUM!, you should pick up and read the likes of Keyboard and Electronic Musician. Although not geared specifically towards drummers, these magazines are full of ads and articles that show the hardware, software, and techniques that are available and happening. Another source of information is in the pro audio and keyboard departments of the your local music stores. Stop playing the V-Drums for a few minutes, walk out of the drum department, take a stroll through these other departments and check what's on the shelves. It's another world out there.

Big Things to Consider

The first is the client's needs. Do they need a one bar loop, a two bar loop, or a loop set of 12 parts? Also consider how the end result will be used – is it for live performance, a song demo, a CD project, or a jingle? The answers to these questions put me into a particular work mode. For instance, a jingle will probably have a limited budget when compared to a union record session. A bigger budget means there will most likely be more time to spend on the needed loops. I've seen fairly big budget record sessions spend a day on one two-bar loop. On the other side of the coin, I've walked into jingle sessions and walked out ten minutes later, finished. Most often the client will have recorded examples of what they think they want. This is especially true on jingles, as jingles have a "temp" track of music the producer likes and has fallen in love with, but doesn't want to, or can't afford to license.

The second consideration is a musical one. What style do the loops need to be? They could be some kind of techno thing, open alternative slosh, or who knows what. You have to be prepared to deal with any eventuality. In my L.A. studio days there was more than one time that I told the contractor I had an instrument I didn't even know existed, let alone owned. Such is life. Take some chances, but be prepared for anything!

The third deals with the technical side. What is the recording format? Could be anything from standalone hard disk recorder, to 2" tape. This is important because giving them the most killing loop set in an incompatible format will make extra work for them, and they hired you to make their life easier. Ask what format they're working in. Is it Roland's VS-Series hard disk recorders, computer-based hard disk recording such as Digidesign's ProTools or MotU's Digital Performer, or tape? They may be working in some or all of these formats. Then there are the parameters that make the budding loop maker shake with fear and bite the end of their pencil – sound format, sample rate, and bit depth. Have no fear; I'll cover all of that later in the article.

Although sometimes uncomfortable, a discussion about dead presidents has to take place. You know, the ones on the big-head green bills. After finding out what you think will be involved with the loop project, discuss the compensation (or lack thereof) with the client. This sidesteps misunderstandings and potential hard feelings later. Although making money right from the beginning would be great, I'd encourage you to get your feet wet in the digital realm by doing any projects that come your way, even if they don't pay. It's better to make mistakes on these projects than your "big break." Look at these opportunities as your real life schooling.

Things to Think of While Looping

You've done your homework, know what the client wants, and are back at your studio. Take inventory to see if there are any sounds or gear that you don't have. Friends are always ready to help with gear, sounds, or expertise. Once you have everything together, you're ready to work without distractions. Determine if the loops will be all MIDI instruments, all acoustic, or some combination of the two. Start creating. Not everything you produce will end up in the client's hands, but keep this work anyway – it might be usable at a later date.

Once you're done with the loops, don't run off and deliver the final mixes (unless you're up against a deadline). Listen to them the next day. Play them on different stereos, including car stereos and boom boxes. I worked with a recording engineer in L.A. who didn't let a mix go until he heard it in his '84 four-door Honda Accord.

Always double-check the loop delivery format. While sample rate can be often messed up, it's more likely to make a mistake on bit depth (don't worry, we're just about to talk about these things).

Sound File Format

This is perhaps the largest source of problems for newcomers to digital audio. Quite frankly, it can be a stumbling block for us veterans, too. My occasional problems stem from miscommunication, but most newcomers will find that their problems come from not having experience and knowledge of all the different sound file formats out there. Ask the client what format they need the loops in (heck, they might not know). If they don't know, ask the engineer/sound guy, or find out what recording platform they're recording or playing them back on – this will give clues. Audio sound files are recognized with a three- or four-digit suffix (.xxx) after the file name.

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The following are some of the common formats:

AIF (Audio Interchange Format). This is a computer file format. AIF is most commonly found on Macintosh computers, but many Windows programs can also read these files. These sound files can be "mono," "split stereo," or "stereo interleaved" files. Split stereo files contain two separate-but-linked files whose file name ends in "L" and "R." Interleaved files show up as one stereo file. While many dedicated sound editing programs can read all three types of AIF files, most of the popular multi-track hard disk audio software and hardware out there only reads mono and split stereo files, but will import interleaved stereo files. This format can embed "loop points" in the file. This file is capable of most sample rates and bit depths.

SDII (Sound Designer II Format) This file format, pioneered by Digidesign, is similar to AIF. Stereo files in this format are commonly "split stereo" (two mono sound files that make up one stereo file), but may also be interleaved. These files must be interleaved before they can be burned to an audio CD. This is the native format of MotU's Digital Performer, and Digidesign's ProTools hard disk recording programs (ProTools HD 192 now uses the WAV format).

WAV (Microsoft Windows Audio Format) This is a computer file format that was first associated with Windows PCs. Although still most common on PCs, Macs are also able to read this format. It can contain marker information, but not loop points. This file is capable of all sample rates and bit depths and can also be mono or stereo files.

MP3 A highly compressed audio format commonly used in Web and multimedia presentations, as well as portable audio players. Its files are about one-tenth the size of AIF and WAV files of the same length.

RX2 The format used in the Recycle software from Propellerhead. A unique format that contains imbedded "slice" information that allows you to stretch and compress a file without changing the pitch. It also contains MIDI information about where the timing of the slices falls, that certain software programs can import, thus making changing the feel of the loop much easier.

Sample Rate

Sample rate is the number of times per second a sound has a snapshot taken of its waveform. CD quality is 44.1K, or 44,100 snapshots per second. Half the sample rate is roughly the highest frequency that that sample rate can represent. The 44.1K sample rate was chosen because it can represent frequencies of up to around 22K, which covers the complete human audible hearing range (for most of us anyway).

Common Sample Rates: 22.05K: Multimedia & Web presentations 44.1K: Audio CDs 48K: Video production 96K: DVDs

Bit Depth This is the number of binary 0s and 1s used to describe each snapshot. The more bits, the more accurately the sound is reproduced. Although audio CDs use 16bits, 24bit is now the common recording standard – it just plain sounds better. The higher the number of bits used, the wider the dynamic range of the sound.

Hardware

Back when I first started creating loops (hand me my arthritis medications please), the music technology available for creating and editing loops made the process somewhat complex and time consuming. Back then, there were no CD-quality hard disk recorders, and practically no sound editing software. Personal computing power was limited and expensive. Loops were created and sampled into stand-alone samplers. Editing was done by numbers that represented samples per second, or by ear (muffled gasp). All this has changed in the last decade. We now have inexpensive, high-quality gear that makes the recording and looping process much easier.

My looping setup is pretty simple. Depending on the client, I'll either use a Roland VS-2480 standalone hard disk recorder (a complete studio in a box), or a Macintosh G4 with a Mark Of The Unicorn 828 firewire audio interface. Both setups are similar in cost.

The VS-2480 is truly a studio in a box. It has built-in microphone preamps, expandable effects, and motorized faders. Put sound in, and out pops a finished audio CD. When you plug a video monitor, keyboard, and mouse into the 2480, the lines between a computer and standalone hard disk recorder are blurred. It's the only choice if you're computer-phobic. Plus, I've never seen a VS recorder crash – wish I could say that for computers.

Now, I've been a computer geek forever. My first computer was an Apple Macintosh I bought in March of 1984, and I have owned countless Macs since then. The new 800Mhz iMac G4 and the MotU 828 are the basis of my computer hard disk recording system these days. The iMac is compact, fast, and has a LCD flat panel display that is easy on the eyes, which is very important when you spend lots of time in front of the screen. There are good PC-based recording systems out there, but I admit that I'm biased.

To deliver the loops to your client, you'll need to have a CD-R drive (to burn a CD of your work). Most new computers come standard with at least a CD-R drive. My new Mac will even burn DVDs!

You'll also need some sort of speakers to monitor your audio. Don't use stereo speakers! There are lots of great inexpensive studio monitors available, both powered and un-powered. With studio monitors you'll more accurately hear what's truly going on with the sound.

The previous two examples of hardware are at the top end of the home/production studio scale. There are also some much less expensive pieces of gear that are available to get your feet wet in looping. Although I won't discuss these in depth, check out the Roland SP-303 Phrase Sampler, and the brand new Roland MC-09 Phrase Lab. The Phrase Lab has many of the same capabilities as the software that will be discussed in the next section. They both use inexpensive Smart Media memory cards to store and transfer files between units and computers. Both these pieces are an inexpensive, great sounding way to get into looping.

Software

Although standalone recorders all use software, which in most cases can be updated, it is relatively transparent to the user. This is not so with computers. The world of music software for computers has exploded in the last few years, and offers many things that were once available only through hardware.

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Computer based recording systems need both hardware and software to make them run. Because I've been using versions of this software from the mid-'80s, I use Mark Of The Unicorn's Digital Performer for my digital audio and MIDI recording. There's no sense in learning a new program unless you must. Digital Performer is a Macintosh-only program that has done a great job of seamlessly blending together both the digital audio and the MIDI aspects of computer based recording. There are other programs that integrate MIDI and digital audio well. These include Emagic's Logic and Steinberg's CubaseVST (both Mac and PC). Digidesign's ProTools is the most widely accepted digital recording format, but, in my opinion, lacks the elegant integration of MIDI. ProTools' premier status may soon be challenged, as Apple Computer purchased Emagic a few months ago. Apple has taken a big bite of the video editing market away from Avid (the parent company of Digidesign) and seems to have set its sights on the audio market as well. As a note, Digital Performer 3.0 and above can open up recordings made in ProTools. I recently did this, and it works well.

Even though there are tools in all the above programs to create and edit loops, I use a Mac-only audio-editing program from Bias, Inc. called Peak 3.1 to do all my loop creation. It can import and export most audio formats and apply EQ and effects. But its greatest feature is called Loop Surfer. This feature lets you set a beginning and ending loop point based on numbers of beats and tempo, then actively drag this "loop grid" around to any point in the audio file while the file is playing, which makes it very easy to find a loop. This one feature has saved me a great deal of time, and is worth the price of the program alone. There are similar products available for PCs, so consult your local digital audio guru for more information.

To burn your finished files using a CD-R drive, you'll need CD burning software such as Toast from Adaptec. A "lite" version of Toast (Macintosh only) is generally bundled with the CD-R drive. Easy CD Creator is a popular PC CD burning software, and will most likely be bundled with the drive. Other versions of both these software packages have more advanced features that can be purchased later on, but the bundled versions will work well to get you started.

Although this software will allow you to create crushing professional loops, there are two really cool programs that can drastically modify existing loops, and create loops with drums, percussion, and synth sounds completely inside your computer! Because songwriters can only go to the loop well so many times, there's a program called Recycle from Propellerhead. Among many other things, this program allows you to change the tempo of a loop without changing the pitch, as well changing the pitch without changing the tempo. This couldn't be done without computer technology. The second program is a blast to use, and allows you to create in different ways. It is Reason, also from Propellerhead. I could spend multiple pages just scratching the surface of it. Seek out a demo of this software, it rocks! Both of these programs are available for Macs and PCs.

Hey, let's make some loops.

Example of Loop Creation

Since this article focuses on loops that sound acoustic, rather than loops based on electronic sounds or MIDI, I'll record an alternative-style groove at 88 beats per minute for the loop examples. Leaving the subject of microphones, preamps, and other outboard gear used to record acoustic drums for a later time, I'll be playing my V-Drums for this article.

Fig. 1. A level between 75—100 percent will minimize distortion while recording drums.

When recording drums, or any instrument for that matter, make sure there is a good, strong level on each track, without the sound distorting. This is true for analog (tape) recordings, as well as digital recordings. Analog distortion doesn't sound very good, but digital distortion is really nasty sounding. You'll know it when you hear it! The hotter the recorded level, the better the signal-to-noise ratio, and the wider the dynamic range. Digitally recorded files can always be "normalized," a process that raises a sound file's level to near maximum without distorting it. This is something you can do if you have to use sound files with low-recorded levels, but by no means is it the best course of action. A level of between 75-100 percent of maximum is best (see Fig. 1).

Because V-Drums have eight outputs, recording them is very much like recording acoustic drums, but without much of the hassle. For these loops the audio is split out into seven outputs – kick, snare, stereo cymbals, hi-hat, and stereo toms. The stereo cymbal and tom pairs contain panning information. For example the four toms only take up two tracks on a recorder, but their audio still moves gradually from one side to the other (depending on how they are panned). To accomplish this with acoustic drums you would have to use four microphones and four tracks on a recorder.

Fig. 2. Four main windows used for navigation and editing in Digital Performer.

Fig. 2 shows the four main windows used for navigation and editing in Digital Performer (later on referred to as DP). Window "A" contains the transport controls and information about the current file. This information includes some of the things we discussed earlier. Just to the right of this window you'll see the sample rate and bit depth at which this DP file is recorded – 44.1K sample rate and 16-bit depth. Looks like CD quality to me.

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The individual MIDI and audio tracks are found here in window "B," although since there are no MIDI tracks, you only see an audio overview. The ability to edit audio and MIDI together in this window is where DP shines. Window "C" is the mixing board. You add effects and EQ here. "D" is the audio-editing window. This is where you can edit the individual tracks. You have the ability to slice up the audio, move it around, and even replace notes. If a section of the recording is a great sounding loop, but a snare hit (or any other sound) sounds bad, you can find a hit elsewhere in the recording, copy it, and replace the bad one! If you look at window "C" of Fig. 2, you can see that I already did the mix for these drum tracks; panned things, changed volume levels with the faders, as well as added EQ and effects. This is all pretty standard drum mixing stuff.

I recorded 18 bars of drum groove with the hope of getting at least one two-bar loop, and perhaps a fill or two. By recording more groove than you need, you give the time a chance to settle down and increase the odds you'll find a good loop point. Unsteady time and subtle changes in drum and cymbal sounds can affect how well an acoustic loop will sound when repeating itself. This is less of a problem with more electronic sounding loops, because the sounds are inherently more consistent. The time aspect is obvious, but if the sound changes color too much you'll begin to hear the repetitiveness of the loop. The shorter the loop the more obvious the repetition tends to be. There are times when this can be a cool sound, but most of the time it isn't.

The second time I listen to what I've recorded, I use DP's marker feature to label the good and bad spots (there are four markers above the recorded tracks). The inserted markers list possible places to grab a couple of fills, a two-bar loop that works well, and even a marker that points to some not very tight playing on my part. Keeping track of the bar numbers of the good and bad spots saves a lot of editing time later on, when the final editing is being done in Peak. Use the repeat feature in DP to audition possible bars for looping. The red arrow at the top, middle of window "B" points to the internal two-bar repeat I've set up in DP to hear how bars six and seven loop around on themselves. These turned out to be the best sounding both musically and sonically. This will be the two-bar loop we'll isolate in Peak. The fills will come from the first bar and bars 15-16.

Mixing is an educated guessing game when you're doing so without the other band parts. My experience is that the low end of the drum mix needs to be louder and have more punch than you think, otherwise when the loop is used in a song it'll be too thin. When mixing, reference CDs with similar drum sounds, as well as drum sounds you like. Sting's Ten Summoner's Tales, and Jonatha Brooke's Steady Pull are two CDs I always have around these days.

After all this listening and marking, I mix all the tracks down to a stereo file (remember, DP uses split stereo files as its sound format) by bouncing all the tracks to disk. Now it's time to open the stereo mix in Peak.

Fig. 3. The complete raw mix in Peak.

With easily loopable measures already identified in DP, I use Peak (Fig. 3) to do any surgery on the loop needed to make it sound and feel better. Be careful though, it's possible to edit and correct the life right out of the loop. We use little pushes and pulls in time to create great feels and character in our grooves. Editing a loop is a bit of a tap dance between making it rhythmically tight, but still grooving.

Fig. 4. The cursor is placed at the beginning of the waveform after expanding it around the downbeat of bar 6.

Fig. 5. A perfect loops end point is inserted by Peak.

Fig. 3 shows the complete raw mix in Peak. The loop we defined earlier at bars 6 and 7 is selected with Peak's Loop Surfer feature. Since we already know that the two-bar loop we want starts at bar 6, I listened to the mix from the beginning, and stopped playback right at the downbeat. I then expanded the loop waveform around the downbeat of bar 6, then placed the cursor right at the beginning of the waveform (see Fig. 4). After opening up Loop Surfer (command-J), you can plug in the number of beats (eight), and tempo (88bpm) and a perfect loop end point is insert by Peak (see Fig. 5). Voila! We have a perfectly timed loop, right down to the sample. Our mom's would be proud.

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Now, the loop is selected and pasted into a new stereo file containing only the selected loop. This loop is almost done, but not quite. You see, it's a two-bar loop, and we have to see if it will loop well on itself at a one-bar loop length. We can even take this further and see if it will also loop well at two beats, and even one beat! You can even edit down to the sample level with Peak. If you need to check timings of subdivisions of less than one beat, you'll have to do it without the help of Loop Surfer, as the smallest subdivision it can deal with is one beat. A little program I wrote called SamplCalc 2.0 is available for free at my web site (http://mikesnyder.net/SamplCalc2.0Folder.sea) to help you calculate these smaller subdivisions (Mac only). Play around with snipping some audio here, and adding some there, it's amazing how small changes in timing will drastically effect a feel. When you're satisfied with the fruits of your looping labor, save the loop in the sound file format you need, repeat for any other loops that you need, and you're done!

That's It

These days all bets are off as to what is a good or bad drum sound. Some of my coolest loops were done with a funky old microphone normally used as talk back mike in the drum booth. Experiment and create as many loops as possible, every groove, style and drum sound is valid. It's just like practicing rudiments – the more you do it, the better you get.

When not in an airplane on his way to a clinic appearance, Mike is an L.A. refugee happily living, performing and recording in Portland, Oregon. He also often wonders why people use PC's instead of Macintosh's. Mike can be reached through http://mikesnyder.net