Music is the recording engineer's raw material. Even the best engineer can't make a good recording unless the music is up to scratch. Music, one might say, is made up of three components: the notes, the arrangement, and the performance. In this article of the 'Recording Techniques' series, I am going to concentrate on the very relevant topic of musical arrangement. The arrangement of any piece of music is as important as the musical ideas themselves. Think of it as a language that helps those ideas be put clearly across to the listener.

Let's look at exactly what an arrangement is, and then examine how arranging techniques are of interest both in the performance of music and to the recording engineer.

Imagine a songwriter or composer sitting at a piano, thrashing out notes, probably humming a tune at the same time, and scribbling away on a sheet of music manuscript paper. What he or she writes is probably as close as you can get to the notion of a musical idea in its pure form. Strictly speaking, what is written down is a piano arrangement, but it bears the same relationship to a fully developed arrangement as a storyboard sequence of sketches bears to a motion picture in glorious Technicolour.

From a sketched piano arrangement, an arranger or orchestrator could build up a full score for a whole orchestra of instruments. The notes in the piano arrangement would all appear in the score, distributed among the various instruments, but the arranger would flesh out these few notes with ideas of his own, thus developing the composer's rough idea into a fully worked out composition. The old-time great composers were, on the whole, their own arrangers, but in many modern forms of music it is now very common for composing and arranging to be individualised tasks.

Sometimes, arranging isn't a process that is thought about consciously. The arrangement may be more or less dictated by the combination of instruments used. For example, the archetypal pop group line-up - dating back to the Fifties and Sixties - is two guitars, bass guitar, and drums. In a group like this, the roles of the instruments are pretty well fixed. Each musician plays what seems appropriate for the song, and the arrangement develops without anyone having to take it upon himself to organise.

THE ESSENTIALS OF ARRANGEMENT

Any musical arrangement will have six basic features, all present to a greater or lesser extent. These are: Melody, Harmony, Bass, Motion, Rhythm, and Decoration. These are not standard textbook headings, but they will help me to explain how arrangements are built up.

Melody. A tune is - obviously - a sequence of single notes. But think about what those notes are doing. They are telling a story, leading from one note to another, forming a pattern which lingers for a short time in the memory, until a new pattern begins. A good tune - even a mediocre tune - has a quality which makes you want to continue listening until the next note, and the next, and so on. The melody may be the raison d'etre of a piece of music, or may be used as a constructional device to assist another more important feature.

Harmony. Back in the midst of musical history, there was a time when harmony hadn't been invented. The best they could do was for everyone to sing the tune in unison or in octaves. Harmony is like a room in which the melody lives. It may be a comfortably furnished room, or it may be austere. Sometimes it is a vacant room - there is no melody within.

Bass. The bass is the foundation on which the rest of the arrangement stands - but it may take on aspects of melody and harmony. It will probably also contribute to...

Motion. Motion is my term for the elements of an arrangement which, apart from the melody, drive the music forward. This may be done by skillful use of the harmony and bass, or motion may be achieved with a specially dedicated musical line.

Rhythm. Rhythm is not the same as motion, but is one of the elements that might create it. Rhythm means repetition - of drum or percussion patterns perhaps, or maybe just a sequence of accented notes.

Decoration. When the arrangement is built up and is functioning properly, additional layers of decoration may be applied. They are not structurally vital, but they add surface glitter and ear-appeal.

Let's apply these six features to the simple two guitars, bass and drums line-up and see how they work.

In the case of a song, the melody will simply be the vocal line - so that's soon dealt with. The main harmony of the arrangement is provided by one of the guitars, traditionally called the rhythm guitar, playing chords to suit the melody. The bass is, of course, provided by the bass guitar, and rhythm by the drums.

Apart from the drums, where does the motion in the arrangement come from? If the rhythm and bass guitars play just one chord plus bass note per bar, then there won't be much motion. Motion is created by the rhythm guitar strumming, and the bass guitar playing extra notes which are not strictly essential to the support of the harmony.

Decoration is the responsibility of the lead guitarist, who plays 'licks' and counter melodies, and the drummer who plays a 'fill' every so often, probably at the ends of the musical phrases.

The guitars, bass, and drums line-up didn't develop by accident, as you can see. It can provide all the features that a musical arrangement must have, albeit at a fairly simple level, with a minimum of instrumentation. Providing one or more members of the band can sing, this combination can produce a full, satisfying sound.

Another combination of instruments that didn't just come about by chance is the symphony orchestra. Orchestral music may not be to everyone's taste, but arrangement-wise, it has much in common with modern styles. The standard symphony orchestra has four instrumental sections: strings, woodwind, brass, and percussion. Of these four sections, the busiest is usually the strings. (One reason for this is that it takes a lot more energy to play a wind instrument and the players need to rest during the performance). The string section of the orchestra - violin, viola, cello and double bass - cover the full spectrum of useful musical notes, they are capable of a wide range of dynamics, and can play in a variety of styles. Because of this versatility, many orchestral arrangements use the strings as the basis of the music, and the other instruments as a contrast or as reinforcement.

Certain instruments of the orchestra have particular roles and do not depart much from them. For example, the French horn, in its earlier days before it had valves, was often used to 'hold' the music together. While the strings and other wind instruments were playing the musically interesting parts, the horns played long, sustained notes which had the effect of binding the string and wind sounds together. The piccolo, a half-size flute, is rarely used on its own. It has a very bright, piercing timbre, and when the full orchestra is belting out a fortissimo passage the piccolo can still be clearly heard, and gives the sound a cutting edge. The tympani are tuned kettle drums nestling among the other instruments of the percussion section. They have two functions - to provide accents in loud exciting passages, and played softly to add atmosphere and mystery when the music is quiet.

Even if you don't have access to a symphony orchestra to perform your music, modern instruments such as guitars, synths, and samplers fulfill many of the same functions as orchestral instruments. The basic way in which music works remains the same.

RECORDING ARRANGEMENTS

Once upon a time, recording - even multitrack recording - meant capturing an existing performance arrangement on tape. The musicians had worked out what they were going to play, were probably capable of performing the piece perfectly well live on stage, and simply recreated their live performance in the studio, with extra precision and perhaps with a little extra decoration added.

Recording, as it is practiced today, is much more involved with building up the arrangement as the recording progresses. That's why a knowledge of arranging techniques is important to the engineer. When finished, the recording will have to fulfill a number of criteria. Whether it succeeds will depend on the arrangement at least as much as the engineering skill and the recording techniques employed.

Apart from matching the mood of the song or piece of music, the arrangement should provide a sound which is adequately full - not a sparse sound, lacking in substance. Fullness can, to a certain extent, be enhanced by appropriate recording techniques, which I shall mention later in the series, but it is mainly down to the arrangement to achieve this.

The arrangement should also be interesting, with the appropriate amount of decoration - but not so much as to clutter the music. The sounds of the individual instruments should integrate so that they blend together well, and they should provide a good balance between the high and low end of the frequency spectrum.

One further point is that the listener's interest in the music should not diminish during the course of the piece. It may diminish, but it is a function of the arrangement to make sure that it does not.

Although I have so far been commenting on the instrumentation of an arrangement, another important factor in arranging something like a song is to get the musical structure correct even before thinking about instruments. Sometimes this doesn't apply, because the structure cannot be changed. It is not customary, for instance, to alter the structure of a classical piece in a simple arrangement. But when the options are open it really pays to think about which bit of music goes where, whether the song should start with a verse or chorus, whether a different introduction would be better, or how should it end. There are lots of things to think about.

Here's one little structural trick, which I'll throw in at this moment, for when the rhythm of a song seems to sag halfway through - perhaps because the phrase lengths are too regular and the ear has become just a little jaded. The trick is to miss something out - a beat or a bar. If a song consists of regular eight-bar phrases, then cut one phrase to seven bars towards the end of the song. Or cut the last eighth note (quaver) from the last bar of the phrase. Both tricks, if applied suitably, will have the effect of throwing the song forward, increasing its momentum and making the listener's ear prick up. An analogous technique, which has perhaps been a little over-used, is to change key - either a tone or a semitone upwards - near the end to give the song a lift. It's a cliche, but it works.

Back to the instrumental content of the music: let's imagine that a song is being recorded on multitrack from scratch, adding musical lines instrument by instrument as seems appropriate. I'll start with some basic building blocks...

Since it's a song, then the instrument responsible for the melody line is already fixed - the voice. To support the melody there must be a bass - just the minimum amount of notes to tie in with the vocal line will suffice for now. A simple way of adding motion and rhythm would be drums. Notice how in that last sentence I set out what I wanted to achieve, and then how I intended to achieve it. It's obvious in the case of drums, but later on there may be options.

Drummers, or drum machine programmers, use two very powerful methods for propelling the rhythm forwards: (1) the off-beat snare, and (2) the hi-hat pulse. Almost any pop, rock or jazz piece of music uses these two techniques, because they are so straightforward and so powerful. To emphasise the off-beat snare, a bass drum beat is added at the beginning of each bar.

It is really getting down to the nitty-gritty of musical arrangement to think about the function of each beat in a drum pattern, but it's much better to know why something is done than just to do it because that's the way everyone else does it. Two other drum tricks: instead of having the bass drum on beat 1 and snare on beat 3 of a four-beat bar, put a bass drum pulse on each beat. And/or add a hi-hat pattern of 16th notes, with an accent on the third pulse of each group of four. Trevor Horn, through Frankie Goes To Hollywood, made a mint out of this one!

Now we are getting somewhere with melody, bass and rhythm, the rhythm supplying some of the necessary motion. Next on the list is harmony. The standard arrangement trick for filling out the harmony of a track is to use a pad. Once again, the pad is a simple idea but it works. There are other ways to achieve the same, but the pad is definitely the most used.

So what is a pad? It's just a straight series of chords played on a sustaining instrument to the harmony required by the tune. No movement, no interesting features, just bland straight chords. Commonly requested types of pad are the 'string pad', which could be real strings but is more often a synth playing a string patch. It doesn't usually sound much like real strings, but it has a similar texture and harmonises and fills out the song at the same time. The 'Rhodes pad' is similar but played on a Fender Rhodes piano, preferably with a chorus effect, though nowadays it's more likely to be the DX7 synthetic alternative. Since a piano sound doesn't sustain like strings, the notes are usually unobtrusively repeated.

The beauty of the pad is that it provides a base for subsequent musical parts to work on. It's like an artist applying basic areas of colour to his canvas before adding in the detail with a fine brush. Sometimes, as recording progresses, you find that the pad has served its purpose. You have built up enough extra layers, each having different musical details, to give a full enough sound without a pad.

There are other alternatives to the string or Rhodes pad; in fact, any bland sustaining sound will do. Sometimes a pad with more character is used, so much that it becomes interesting in its own right. The Pet Shop Boys' West End Girls is a fine example of this, where the pad sounds like - but probably isn't - a rusty old Mellotron with a severe case of moth infestation! It wouldn't suit every track, but it suits that one.

MUSICAL MOTION

Our song now has a full sound, but it has only rhythmic motion; it also needs musical motion to give it direction.

With the existing instrumentation, this can be achieved by making the bass more mobile, with extra harmony and passing notes. Another simple way is to add some more chords, but this time with some rhythmic interest. A neat trick to add motion is to have a 16th note pulse, either chords or single notes, running through the song. This always works, but you can't do it in every song or it becomes an easy way out, a substitute for creative thought.

On top of this basic structure goes the decoration to provide the necessary interest. The decoration can be pretty well anything: extra instruments, contrasting combinations of instruments, changes of instrumental timbre, syncopated rhythms, and so on. A good decorative device, which also helps pull the song along, is the counter melody. This is a melody, probably instrumental rather than vocal, which runs together with the main tune; but where the main tune 'ebbs and flows', the counter melody should 'flow and ebb', maintaining the overall level of activity.

One last technique I can mention is employed in just about every track ever recorded - the 'build up', or simply 'build'. With an unchanging combination of instruments, even a very well arranged combination, repetition will gradually produce boredom. One way to get around this is to use different combinations of instruments over the duration of the piece. This is good for lengthy classical pieces, but not for a modern song recording. One of the typical aims of a song recording is to create a single atmosphere or mood that lasts for three minutes without really changing at all. There are tracks that are more complex, Phil Collins' In The Air Tonight being a good example of a song with two distinctly different sections. But if, as usual, the song has to retain the same feel throughout, then you can't chop and change instruments or sounds.

The answer is to start the track fairly simply, and add more and more interest as the song progresses, as the ear gets bored with what it has already heard. By the end of the song, the arrangement can often be quite complex with much decoration - and decoration in the vocal line, too. In other words, it builds up.

I can't describe every arranging trick and technique, because there are probably thousands of them. That's why there are specialist arrangers, who can command their pay through a good knowledge of how to get the best out of a piece of music. But the main trick is to know what you want to achieve, and to acquire, through experiment and practice, a range of techniques to allow you to do just that. Listening to the arrangement of a track that you think is musically successful is bound to help. But don't forget that, sometimes, what works for one person may not necessarily work for another. Develop your own arranging skills and techniques and perhaps you will come up with a completely new and original sound.