When it comes to music sequencing, you're probably used to extracting almost every last ounce of performance possible from your computer. You've quantised, edited, transposed, and scaled; trimmed velocities, controlled controllers, and shifted some note timings around to add a more human feel. Still, your song isn't finished yet -- unless you've tweaked the tempo track.
Although sequencers and drum machines produce metronomic tempos, humans do not. Subtle tempo changes, inserted over several measures or just in selected parts of individual measures, can build anticipation, humanise a tune, change moods, and add a certain spark to a song that makes it more appealing.
It's particularly interesting to note the 'tempo maps' of classical pieces. Ray Williams (involved with DNA Groove Templates and Steinberg software) analysed two different pianists playing Beethoven's Moonlight Sonata and graphed the tempo track variations; although there were significant differences between the two players, both looked like an outline of the Alps.
However, the tempo track for most sequenced tunes looks as flat as the Sahara -- which can also flatten out the music. If you're ready to add more life to your tunes, check out these tips...
Sometimes different sections of a tune will sound like they are dragging (even though there's a consistent tempo throughout the tune) if the sections have different rhythms. Here's a simple example.
Programme eight measures or so of a drum part at 120 BPM (beats per minute), where the kick drum hits on every beat, and the closed hi-hat on every offbeat.
This gives a light, bouncy feel, as found in lots of 'Afropop' and world beat-style tunes. Now follow that with eight measures of a more rock-orientated drum part, also at 120 BPM, where both the kick and closed hi-hat fall on every beat.
Finally, follow the rock part with eight more measures of the Afropop part, again at 120 BPM. If you listen to the three parts consecutively, the second part may seem to drag in terms of feel (although not necessarily in terms of tempo) compared to the first part. The third part will probably feel faster in relation to the second.
Now increase the tempo of only the second rock section by 1 BPM, and play all three sections consecutively. You'll notice a definite difference in feel compared to when all three parts were set to the same tempo. It's a matter of personal preference which feel you like better, but the one with the changed tempo often sounds the most appropriate.
This is just one example; there are other situations where a part of a tune will seem to drag or rush. Try the 1 BPM solution and see if this fixes the problem.
The following technique is ideal for transitioning from one part of a tune to another (eg. verse to chorus, chorus to solo, chorus to verse, etc). It involves dropping the tempo by 1 BPM halfway through the measure before the next part, then resuming the normal tempo halfway through the next measure.
This raises the anticipation level before the next part appears, since the slight slowdown prepares the listener for the fact that something is changing. Increasing the tempo after the next part begins provides a fairly smooth change from tension to release. However, you might want a more drastic change in tension, accompanied with a quicker return to the normal tempo. A slight variation on the above works well.
In this example, the tempo drops 1 BPM at the third beat of the measure before the next part, then drops 1 more BPM at the fourth beat. If there's a drum fill going on here, the effect is very cool, particularly with rolls -- you're pole-vaulted right into the next section. Since the following section resumes the normal tempo immediately, you're snapped back into the flow of the song.
The first approach seems to work well with verses and the second for choruses or solos, but you really have to judge each case with your ears and programme appropriately.
Any time there's a 'dramatic pause' in a song, a tempo change can reinforce it. For example, I was recently working on a fairly straight-ahead dance tune where, after the verse, there was a sparse 2-bar pause with only voice, bass, and a little vibes. This was the high point of the song, where the singers sang the title. To give them more time to really caress the words, I dropped the first measure's tempo by 1 BPM and the second measure by 2 BPM. Because there wasn't any steady rhythm in the background, the effect was of a brief elongation of time that really emphasised the words.
Sometimes you'll finish playing some fabulous solo, and it doesn't seem quite right to proceed immediately to the next measure. In this case, it's a good idea to allow just a tiny pause so that the listener can 'reboot' between leaving the solo and starting the next part. A drastic drop in tempo for a very short period can add such a pause .
It's best to insert this change between notes, or you'll have some weird timing distortions on any notes that play during the tempo drop (sustaining notes are not a problem).
Another type of common pause is a 'false ending', where something sustains for a measure or two before the main melody or hook returns. Inserting a drastic, short tempo drop just before the return of the next part adds a further element of surprise, because the brain expects the tune to return on the beat; when it comes in just a fraction of a second late, it introduces an added element of interest.
Most sequencers let you insert measures into a song, but few let you insert spaces smaller than a measure, such as an eighth note. The need for this arose on a tune that started with a particular melodic line. During the mix, it seemed like a good idea to add some environmental sounds to set the mood prior to the melody line coming in. Unfortunately, when the melody started, the transition between the sound effects and tune was too sudden. So, I decided to add pauses between segments of the melody line, to break it down into multiple themes separated by environmental sounds.
Most of these pauses needed to be much less than a measure long, so I thought I was out of luck. But inserting drastic downward tempo changes between notes slowed down the sequence enough at those points to give the effect of adding space.
The more I work with tempo-shifting, the more it seems like a necessary final step before considering a sequence 'done'. Sure, a sequence can sound okay when playing back at a constant tempo; but try some of these tricks yourself and see if you don't agree that occasional tempo changes can add vitality and interest to a tune.
Increasing tempo slightly is the timing-orientated equivalent of modulating upward by a semitone, since both boost the energy level. For example, assume a 16-bar solo passage where one instrument takes an 8-bar solo, then a second instrument takes the next eight bars. Increase the tempo for the second part by 1 BPM and -- especially if the second part is accompanied by a key modulation -- the solo will take off to another level.
After you've upped the tempo, the question then becomes whether to maintain that tempo or drop back when the next section begins. If you maintain the tempo, a quality of tension remains. If you drop back, there's a feeling of release. The greater the amount of tempo change, the more pronounced the effect.