The Lowdown on Sequencing Bass Tracks
By Jim Aikin

If you've ever tried recording your own bass tracks in a sequencer, you may have discovered that creating a believable, dynamic bass line using MIDI is not quite as easy as shooting fish in a barrel. With Trilogy's acoustic and electric basses, you have the sounds you need for laying down bass lines that will actually fool listeners into thinking they're hearing the real thing. Achieving that high degree of realism, however, requires not only great sounds but also musical taste and stylistic smarts.

Bass players who have turned to sequencing usually have a pretty clear idea how they want their bass tracks to sound. But not everyone is a bass expert -- and not all bass experts are sequencing pros. In this tutorial we'll take a look at a few techniques you may find useful for improving your acoustic bass lines. Trilogy is loaded with electric and synth bass sounds as well, but we'll focus mostly on stand-up bass, since that's an area where sequencer jockeys sometimes need a little extra help.

Listen

To record great bass parts, you need to know what great bass players do. There's no substitute for listening to classic recordings. If you want to cop the jazz bass sound, for instance, check out a few CDs that feature Ron Carter, Ray Brown, Eddie Gomez, or George Mraz. Their solos are amazing to listen to -- but you'll learn more about bass playing by listening to what they do behind the band. Choose a few tunes you know the changes of, and listen closely to how these bassists work with the harmonies in the progression, and how they complement the other instruments. There's a lot more to bass playing than thumping the root on the downbeat and then noodling around!

The bass player will usually stick close to the root, third, fifth, and the seventh of the chord. Higher chord tones, such as ninths and suspensions, don't tend to work well in bass lines. However, a bass player may approach any of these chord tones from a whole-step or half-step above or below. The approach tones are the same pitches as the ninth, eleventh, thirteenth, and suspended fourth, but in a bass line they usually resolve upward or downward to a root, third, or fifth. The approach tones can be played between the major beats, or they can be played on the beat, so that the chord tone comes after the beat.

Here's a quick example that illustrates one way to use approach tones. Instead of arpeggiating a C7 chord straight up and back down (C-E-G-Bb-C-Bb-G-E-C), the player might approach the first E from below with a D#, and then replace the Bb with an A on the way back down: C-D#-E-G-Bb-C-A-G. Try this as a walking bass line using one of the Trilogy acoustic basses.

Jazz bassists sometimes anticipate a beat by a sixteenth-note, or add an extra sixteenth-note just before a beat to give it a little extra push. But they don't do this at the same place in every bar. Try playing that up-and-down line again, and this time approach the high C with an extra sixteenth-note B-natural (producing a Bb-B-C chromatic scale). Or, coming back down, drop an Ab sixteenth-note between the A and the G.

Instead of using a straight chromatic scale to fill in the sixteenth, try playing the sixteenth by thumping the nearest open bass string (E, A, D, or G) below the line you're playing. This simulates the effect of the player lifting his or her left hand momentarily, perhaps while shifting to a higher position. To hear a lick that uses these techniques, plus one of the pitch-bending tricks discussed below, listen to bass_lick.mp3.

This is not the place for a full-scale assault on the techniques of jazz bass playing. And jazz is not the end of the story by any means. Lots of other styles feature great bass players. Fifties Motown and Seventies funk bass are well worth studying in depth. In Latin music, the bass often anticipates the downbeat of each bar by an eighth-note, which pulls the rhythm forward in an exciting way. In country and other traditional styles, the bass tends to stick close to the root and fifth of the chord, except for occasional walk-ups from one root to the next. This pattern is so strongly associated with country and folk music that if you alternate the root and fifth in a heavy rock recording, it will sound corny.

As you listen, you'll hear many tricks far more sophisticated than the few I've suggested here.

Rhythm


The bass is part of the rhythm section. In a real band (you remember those, don't you? we used to have them back in the 20th Century...), the bass player and drummer lock down the groove by listening closely to one another. In particular, the bass and the kick drum almost always accent the same important beats. If the kick supports a particular syncopated rhythm, the bass should do the same.

In sequencing, you can have the bass and kick play the same accents 100% of the time, if you want to -- but it's usually better to let each instrument hit an accent somewhere in the measure that the other one skips. It sounds more like a real band if the bass player occasionally displays a little independence.

One of the more interesting dramatic tricks you can play with a bass line is to leave holes. In an extreme case, the bass and drums might only play the downbeat in every other bar and then rest, letting a soloist or the higher-pitched instruments carry on by themselves. (In jazz, doing this for 32 bars is called a "stop chorus.") But smaller, less obvious holes at strategic spots will give the bass phrases more interesting shapes.

After a break where all of the instruments lay out, the bass sometimes does a lead-in to the next downbeat. This can be a walk-up from a lower note (which might be two or three beats long) or a glissando or smear down from a high note (usually only one quarter-note or eighth-note in length, and sharply accented). If your arrangement calls for this kind of break at several points in a tune, don't always use the same lead-in. Let the bass player do it this time, and the drummer or guitarist the next time. Smears are hard to simulate with a MIDI bass, but with Trilogy's generous complement of sampled smears, you don't need to fake it: Just tap one of the notes in the bottom octave, and you're there.

To Quantize or Not to Quantize

Thanks to quantization, your bass lines can have a rock-steady rhythm. This may or may not be what you want. I tend to quantize the bass, kick, and snare pretty rigidly, to provide a solid framework around which the other instruments can move a bit. If your keyboard chops are better than mine, you may not find it necessary.

When the groove has some shuffle, it's especially important to give the bass, kick, and snare the same amount of shuffle when quantizing them, so that the syncopated offbeat notes will hit together. Your sequencer may have a feature that lets you quantize one track to another track, so even if you've customized the drum track by hand (or played a good-sounding drum part and had the good sense to leave it alone ... or imported one of the Groove Control patterns in Spectrasonics Stylus), you can still get the bass to lock to it. Your sequenced rhythm section may sound more lively if you give other MIDI percussion tracks such as congas and cowbell less shuffle than the kick, snare, and bass, or more shuffle. But the kick, snare, and bass should almost always agree on the feel of the groove.

Little Bends

With Trilogy's acoustic and fretless electric basses, adding subtle pitch-bends to your tracks can promote incredible realism. Again, there's no substitute for listening to how real bass players slide into notes, but here are a couple of ideas to get you started.

First, though, check the BEND parameter in the lower right corner of the panel and make sure your Trilogy preset is set to respond to pitch-bend data by bending no more than two half-steps. You may find that setting it to one half-step works even better at times, because the idea in bass bends is not to bend from one chromatic pitch up or down to another. The idea is to create subtle, barely noticed pitch inflections.

Imagine that you're playing a fretless and playing a lick that involves sliding your left hand up to a note that's higher on the fingerboard. Since the most important thing for a bass player is to keep the rhythm steady (even, on occasion, at the expense of playing an actual wrong note!), your right hand will naturally pick the string exactly on the beat, even if your left hand hasn't quite reached the correct position yet. The result is a very short, very shallow scoop leading into the note from below.

Bass players don't just do this by accident, however. They do it on purpose, to add a pitch accent to a particular note. This technique is shown in the first screen shot, and in the audio file start_low.mp3. (Note: The screen shots in this tutorial were taken using Steinberg Cubase SX 1.0.) You may have to practice your left-hand bending technique a little in order to perfect it. I sometimes draw pitch-bends by hand with the pencil tool, but more often it's easier to just keep recording new takes until I get a bend that sounds right. On occasion I'll record the bass notes in one pass and then add pitch-bends as overdubs.

When you quantize the bass notes, the time relationship between the note and the bend may change slightly. You may need to grab the pitch-bend data with the mouse and drag it backward or forward by a few clock ticks so that it lines up with the note the way it did before you quantized. (I'm still waiting for someone to design a sequencer that understands this issue and handles it gracefully, by moving the controller data along with the associated notes.)

With Trilogy, though, you have another option, one that eliminates the need to fuss with pitch-bend data. Certain of the acoustic and electric bass multisamples include samples in which the player slides into the note from below. These are triggered (in the normal range, not the bottom octave) by MIDI notes with a velocity of 126 or 127. Because of the high velocity, these samples will be played rather loudly, so if you need to slide into a softer note from below, recording your own bend will probably be easier. With a fretted electric bass, on the other hand, MIDI pitch-bends just won't cut it: The fret noise in Trilogy's slide samples is an essential component of the sound.

In jazz and blues, the bass player will occasionally roll a longer note slightly sharp. This technique can add a bit of bluesy "yowl" to the tone as the string rubs against the fingerboard. You might think this change in tone color would be difficult to simulate in Trilogy, but because of the natural evolution of the sampled string tone, adding a slight pitch-bend seems to bring out a quality that's already there. You can hear the results in the roll_sharp.mp3 audio file and take a look at the sequence edit window below to see how it's done. (Note that for this recording I set Trilogy's pitch-bend depth to one half-step. For start_low.mp3, it's set to two half-steps, although the bend itself is only a fraction of that depth.)

Note Overlaps

Editing note lengths in your sequencer is also crucial to getting a good-sounding bass part. Generally, this has to be done one note at a time with the pencil tool. The types of edits you'll make will depend on whether you're using Trilogy's Solo mode.

In Solo mode, Trilogy will only play one note at a time, no matter how the Voices parameter is set. Since a bass player usually only plays one note at a time, you might expect that Solo mode should almost always be switched on. However, this mode also changes how Trilogy's envelope generators respond. In Solo mode, new filter, amplitude, and pitch envelopes will only be triggered when you leave a gap between notes. When two or more notes overlap in Solo mode, the envelopes that have already started will continue through all of the overlapping notes. Solo mode is usually more useful for synth basses than for acoustic and electric basses, though there are exceptions to this rule.

If you're using Solo mode, you may need to use the pencil tool to create gaps between notes at some spots and overlap separated notes at other spots. Because quantizing moves different notes forward or backward by different amounts, it can create and destroy these gaps, changing the feel of your phrase. So always edit the note lengths by hand after you quantize.

When Solo mode is not active, each note will be articulated by Trilogy, even if it overlaps the previous note. However, overlapping notes will create short bursts of low-pitched "mud" in the audio signal, because two notes that are close to the same pitch are sounding at the same time. You may not even notice this effect consciously, but shortening notes so that they overlap less (or not at all) can really clean up the sound of a sequenced bass track.

It's important to switch off the sequencer's "snap to grid" editing feature while using the pencil tool to change note lengths. Bass notes that end on precise rhythmic points will cause the track to sound less human. I always extend the notes so that they end a bit beyond the nearest sixteenth-note grid point, or shorten them so that they end slightly before it. Finding just the right amount of separation between notes, so that some of them are short and punchy while others sustain right up to the next note, is a key to programming lifelike bass parts.

With Trilogy's acoustic basses, raising or lowering the level of the B layer in the mixer can bring you to a still higher level of realism in note-off articulation. The B layer is where Trilogy's release noises are located. These sampled thumps and clicks should usually be subliminal, not consciously heard, but if your computer bass player takes a solo, they'll make a big difference.

When using Trilogy's True Staccato basses, which contain short notes in the upper range of the keyboard, you'll notice that if you sustain the MIDI note just slightly longer than the staccato sample, the release noise will still be played. This tends to sound unrealistic, so with these notes it's especially important to either shorten the MIDI note (so that the release noise blends into the main tone) or lengthen it (so that Trilogy reaches the end of the staccato note data and suppresses the release noise). Another option is to automate the B layer's level using MIDI Control Change 82 messages, so that the release noises show up in your Trilogy performance only when you need them. (ed. note: If you're not familiar with using True Staccato, it is well covered in the Trilogy user's manual, and it's well worth learning as it brings a new dimension of realism to your bass tracks, simply.)

When I was in my 20s (and that was a few years ago), I played a lot of club gigs as a bassist. I no longer own a bass guitar, but I still pay attention to my bass lines. I'm convinced a good bass line is as important as a melody. In fact, it's like a second melody that runs underneath the song. Even in a loop-oriented style of music, where a short bass phrase repeats over and over, that one-bar or two-bar phrase can add real meaning to the arrangement.

If you're using Trilogy, there's no question you're serious about bass. You don't need a lecture from a boring old guy telling you not to be satisfied with throw-away bass tracks. So forget I said anything. Just fire up your sequencer and go for it.

Jim Aikin has been writing about music technology for more than 25 years. His byline appears regularly in Keyboard and Electronic Musician magazines. For more ideas about how to use music technology, you can visit Jim Aikin online at his own site, MusicWords.