modulation

Use of Tremolo - Musical Creativity 42

Alan — Thu, 26 Jun 2008 20:27:29 +0000

I've talked about tremolo as a musical feature before, this time I want to go into more detail.

First things first, let's sort out the guitarists: I don't mean using the tremolo arm/whammy bar or whatever you want to call it ("handle" as my girlfriend called it - and no she won't be picking up my guitars for a while). The whammy bar creates a vibrato feature, not a tremolo. Vibrato alters pitch.

Amplitude

Tremolo is the act of altering the volume of a note or set of notes. For an electric instrument, the simplest to hear is by regularly turning the volume knob up and down. The notes fade in, fade out, fade in, fade out and so on.

It's a great tool for livening up a piece of music. The previous article on the subject covered some more ways of using it.

Recordings

Tremolo features on a lot of famous recordings. Three extreme examples are:

How Soon Is Now - The Smiths

Crush with Eyeliner - REM

What's the Frequency Kenneth - REM

But it's used more subtlely on many, many more recordings. Think of any country song and listen to the guitar. Many of the 1950s and 1960s guitar recordings had tremolo on them. Think Duane Eddy (although he mixed it with vibrato by using the whammy bar a lot). Lots of Elvis recordings featuring Scotty Moore had tremolo. This situation was accentuated and facilitated by the inclusion of tremolo circuits in the guitar amps, e.g. Vox

Types of effect

The common tremolo effect alters the amplitude or volume of the incoming signal apply a regularly repeating pattern before output. The most common pattern is the sine wave, although some FX units also allow square and sawtooth. The output signal increases, decreases, increases, decreases, etc.

The waveform applied changes how fast the signal reaches the extremes and how long it stays there before beginning the journey to the other extreme.

Depth

If the signal is applied completely at 100% depth, then the output will have no signal at the points when the applied FX is at its lowest point, conversely it will have the maximum volume when the FX is at its highest point.

Lowering the depth introduces a less radical effect, to the point that if the depth were at 0%, then there would theoretically be no difference between the input and output. As with most effects, the most appropriate depth is usually somewhere between the two extremes.

Symmetry

The waveform applied so far has been the same on both sides, i.e. going up and coming down. Altering the phase allows more time for the signal to climb and a quicker fall or vice versa. This is great for imparting a slower or a rushed feeling to the track.

Phase

For a stereo tremolo, the default set-up is to have the signal applied equally, but alternately to each channel. Changing the phase control alters the timing displacement of the second channel compared to the first, which can be used to create panning echoes or dotted note rhythms.

No Depth?

I'd usually use a tremolo inline with the signal, either at the recording stage (e.g. between guitar and amp) or at the mixing stage (as an insert). If there's no depth control, then patch the tremolo into a send and emulate the depth by the relative values of the signal and send faders.

For guitarists, if there's no depth control, then you maybe able to use it in the amp's FX loop if you've got a variable dry/wet mix. This may not work well, since the FX would be placed after the pre-amp. Depends what equipment you're using.

Playing with fingers

A classical guitar tremolo technique involves repeatedly plucking the same string with the first, second and third fingers. This is often a bass and/or melody note plucked with the thumb followed by the three fingers or sometimes a fourth is employed but the fingering changes.

The most famous example is probably Recuerdos De La Alhambra by Francisco Tárrega, although I think Agustin Barrios Mangore's Una Limosna por el Amor de Dios (Alms for the Peace of God) shows the technique more.

Various forms of flamenco use a similar technique, sometimes using the thumb plus four finger notes (not necessarily four fingers, often three fingers with one repeated) to get a 5-tuplet pattern.

Pick

For electric guitar, rapidly repeated picking of the same note gives a tremolo effect that can be used in solos. Do it too often and you'll sound you can't move your fret-hand fingers. Best to intersperse it with other techniques. Check out the Ozzy Osbourne recordings with Randy Rhoads, e.g. Tribute, to get an idea of how to fit it into a solo. He doesn't use it that often, but when he does, it works well. Nowadays, watch Matt Bellamy of Muse. There are plenty of others, but they're not coming to mind right now.

In other forms of music, e.g. drag, it can be the main feature. This is more likely to happen on the lower strings of the guitar, with a springy/slap-back reverb. Think Dick Dale. Although perhaps not part of drag, Miserlou (as featured in Pulp Fiction) is a great example of how a simple riff can lead the track. The repeated picking comes from his experience with an oud (or ud).

Part of a series by Award Sounds offering a selection of creative ideas to kick-start or rejuvenate a composition.

Change Key - Musical Creativity 26

Alan — Fri, 01 Feb 2008 12:06:16 +0000

I've written about starting in a new key and also about change in the process of composition before. In this article I want to bring the two together and discuss changing keys within a song.

I like the idea of changing key within a song for a few reasons:

Adding a level of excitement
Changing the mood
Bring the song's key to match the range of notes and timbre achievable from available instruments

I'm undecided whether (1) is just a subset of (2). But it happens so often, I may as well treat it separately.

I'm against the idea of changing key within a song when it's used solely to fill-out the song and prolong the end. If that's the only reason, then don't bother, it smacks of a lack of creativity.

But back to the two or three good reasons.

Excitement

A common technique is to raise the key by a tone or semitone immediately after a chorus, bringing in the new verse in the new key. This is the most common usage within pop/rock music. You can hear it in a lot of songs where the last verse and chorus are up one a key from previous. Sometimes it's just the chorus that's repeated in the higher key.
Taking it a step further, you can change the key several times in the same song. But beware, it can get tiring. At some point is has to end.

One good example is the Snake by Al Wilson. Listen after the chorus for the descending riff that leads into the new key for the following verse. In this case, the song itself is good enough not to need the key changes, but they do add to the experience when you listen to the story. Better still if you're dancing to it.

For a whole load of great examples, listen to the soundtrack for the musical Hairspray. Better still watch the Hairspray DVD. What I've noticed is that the DVD sounds better than the soundtrack CD but I don't know why, possibly just the dynamic compression and how the vocals are clearer in the DVD. That may just be a matter of being able to watch the lips as well. I've yet to listen to the DVD without watching it to test that possibility. Several songs in that movie have key changes, one of them towards the end has several. It almost becomes a game of "spot the key change" every minute or so.

For a more common example, listen to virtually anything by Westlife. Note when they stand up from their chairs and do the arms-wide-open thing? That's usually the key change. It's pure emotional manipulation but it works for them. I don't like that type of key change. The song should have ended some time before the key change, but I'll say it again, it works for them.

Mood Change

You don't have to add a key change solely by going up a semitone or two. You can go down by the same amount or more although that's a lot rarer. You can also change between major to minor keys. Common is the change between a minor to a major key showing the journey the composer wants to take you on, sometimes reflecting the achievement of the main actor or the success of the story. This is the tonal modulation and doesn't require that you change the key, but change the tonal centre instead. Rather than go into this here, there are some good online sources of musical theory, specifically about modulation:

To include other instruments

Each acoustic instrument has a restricted range. That means if you want to use a trumpet, then you're stuck with the notes that can be played on a trumpet, otherwise it's not a trumpet. Good samplers will restrict the range so you don't go beyond the range of the sampled instrument. They should also allow you to deviate and play the trumpet sounds at a different pitch beyond which the trumpet can physically do. It won't sound exactly like a trumpet (mind you, neither do a lot of sampled trumpets anyway) and you can't play it with a trumpet, but you have the artistic license to play as you see fit.

But assuming you want realistic instruments and accurate recordings, then sometimes you have to change the key to include certain instruments in the registers that sound right. I'm not convinced changing key solely for this purpose is beneficial, but I can see places where it could be. I actually have a piece at the moment that I'd like to include the lower notes of the trumpet, but not any other brass. I just can't find a tone and balance that I'm happy with for trombone, tuba, horns. I'm pretty sure it's a trumpet I need, but to do so I think I'm going to have to change the key to suit. In my particular case, I may to change the key for the whole song.

Plus ça change, plus c'est la même chose

So what do you do in the new key? The easy option is to play what you've already played but in the notes of the new key. It's a coward's way out and on its own isn't really creative. However as a lot of pop bands have shown, it's a comfortable experience on your listener.

More interesting is to use the key change to successfully introduce a new theme or convey a different mood. It's more difficult, requires being more creative, but does mean that you'll be giving the audience something more than just slightly altering what you've already done.

And then where?

It doesn't have to end on the second key or even a steady upwards staircase of keys. Take some time to think about moving back and finishing the song in the original key, using the key changes as modulation within the song.

How to achieve the key changes

Rather than re-recording parts just to see if it will work, most full-featured DAWs have a couple of options. Transposing midi is usually easy, just copy the part to a new part (or region) and either drag all the notes up or down or use the transpose setting for that part. Some allow you to change key within the midi programming environment.

For audio parts, you can try the DAW's internal pitch change processing on the new part. If it works and you want to keep it, you've can listen attentively for artefacts and realism so you can decide if the processed file will do or if you need to re-record it. I prefer to record the new part afresh but it's not always possible, e.g. if I don't play that instrument or don't have access to the same exact instrument, signal chain and acoustic space.

A few things to watch out for when changing the key in either of the above ways:

1) You should be making changes only to new parts, just make sure you're not changing the pitch of your old parts.

2) If you're changing between major and minor keys, then watch for the harmonic content. Better pitch shifting routines (whether midi or audio) should allow you to state the new key and scale.

3) Ensure that the pitch correction routine is for musical content, some of the pitch change, time-stretching have specific algorithms for percussion. So choose the one most appropriate to your content.

An easy way

Try the dominant seventh approach detailed at guitartools.co.uk

Edit

I'd written the above article, then came across this site at GearChange.org. I generally agree with most of the site, especially the Westlife comment in the FAQ. I think saying that it's in "no way inventive, interesting or acceptable" is too broad though. Some of it seems to depend on how you define the truck driver's gear change. Whatever the case, the muso article is a great starting point for examining the concept.

Part of a series by Award Sounds offering a selection of creative ideas to kick-start or rejuvenate a composition.