Nothing gives a sonic lift to a band like a great horn section. Whether tucked away in the background or featured out front, the impact and excitement of trumpets, trombones, and saxes bring soul to just about any song.

Not merely any combination of notes will provide a magic sound, however. To make the most of your horn section, it's essential that you learn how to arrange for it properly. Although I don't have space in a single column to tackle this subject comprehensively (a thick book would be more appropriate), I will take a general look at the sonic potential for various horn configurations and reveal some tricks of the trade that classic horn sections have employed over the years. But first, a little history.

The use of modern horn ensembles in popular music grew out of the military bands of the late 1800s. By the early 1900s, rhythm sections had become the backbone of most popular ensembles; in small groups such as the early Dixieland-style jazz bands (which typically included a clarinet, trumpet, trombone, and often a tuba), horn players had more freedom to improvise.

As saxophones' popularity increased, jazz bandleaders once again began writing for larger horn ensembles. Big-band instrumentation evolved into a more or less standard configuration: four saxophone players (two altos, a tenor, and a baritone), who doubled on clarinets and flutes; three trumpets; and two or three trombones. Some big bands included even larger horn sections and incorporated French horns. (Part of what distinguishes the unique sounds of, for example, Count Basie, Glenn Miller, Nelson Riddle, and Henry Mancini from one another is their specific lineup of horn players.) Nowadays the usual big band has five saxes, four trumpets, and four trombones. In general, jazz groups have put horn sections and soloists to good use throughout the past century.

Record labels such as Stax, Atlantic, and Motown and groups such as Blood, Sweat, and Tears; Chicago; and Earth, Wind, and Fire featured small three- or four-piece horn sections as part of their sound. It is possible to hear the echoes of their influence in the music of current artists such as D'Angelo and Macy Gray. Throughout the years, acts such as Sting and Dave Matthews have used a single woodwind or brass player as an improvisational shadow to great effect.

Which musical devices you can employ relates directly to your horn section's size. If you have only one horn player in the group — say, a saxophonist — you're best off using that player for solos and fills around the lead vocalist (assuming you haven't built your group around an instrumental soloist like David Sanborn or Michael Brecker). A single horn really sticks out in a group, so use it sparingly and effectively. If you're looking for that classic rock 'n' roll-saxophone sound, you probably want a tenor sax. The tenor's comfort range is approximately a fourth lower than the alto's, so playing in the upper registers on tenor sax gives the sound a strained, urgent quality that works well for rock, soul, and blues.

Most sax players these days play both alto and tenor (and sometimes soprano) and can easily alternate between the two on the fly. Often you can provide a chart or lead sheet in concert key and let the player transpose accordingly (altos and baritones are in E-flat; tenors and sopranos are in B-flat). Unless you have a specific reason for wanting one sax or another on a tune, the decision to use soprano, alto, or tenor sax is often best left to the player's discretion, based on his or her comfort level with the instruments. Of course, make sure the player's proficiency level is sufficient for the task.

Attempting to fatten your brass parts by doubling a live horn over a sampled horn section doesn't usually work well in a live situation, especially if the live horn is a brass instrument. Although this trick can work fairly well in the meticulously controlled environment of the recording studio, many factors work against it onstage. (A horn doubling keyboard and guitar lines is fine — I'm talking specifically about trying to make brass samples sound more real with a live player added on top.)

In a live environment, the contrast between the live sound emanating from the horn and the electronically amplified brass samples sounds unnatural, especially on a small stage where the audience can hear the direct spill from the band. Larger venues, in which everything the audience hears is amplified, lessen the ill effect somewhat, but I've found this technique still sounds and feels bad to the band onstage. The articulation and timing of sampled horns played from a keyboard and a live horn player hardly ever match — it makes the real horn sound puny and the samples sound even more fake. Save your solo horn for when it really counts.

Adding a second horn player to your group opens up a whole world of possibilities. You can now write harmonies and add unison and octave doubles — the staples of most horn sections. In addition to trumpet and sax unison lines (usually played on alto sax), the two horns often get lines built on harmonic intervals of thirds, fourths, sixths, and octaves (see Fig. 1). In the case of a trumpet and alto combination, either horn can play the higher harmony or octave, depending on the desired effect.

Burt Bacharach's band uses two horn players to maximum effect. The combination of a brass player (trumpet or flügelhorn) and a woodwind player (tenor, alto or soprano sax, alto or B-flat flute) allows a variety of tonal colors. You can easily cop the signature Bacharach sound of doubled flügelhorns by doubling the flügelhorn with an alto flute, producing the required warm, articulate timbre commonly found in his songs.

Horn sections consisting of three or four players expand the possibilities even further as an identifiable sound starts to develop. Steely Dan makes good use of four saxes (usually two tenors and two altos), although all-sax sections can start to sound too big-band if you write a lot of harmony parts. The Memphis Horns, a loose collection of session players, often consists of two trumpets, tenor or alto sax, and bari sax. The famous three-piece horn section of the band Chicago consists of trumpet or flügelhorn, alto or tenor sax, and trombone. Earth, Wind, and Fire's Phoenix Horns used the same configuration as Chicago but added a second trumpet.

Larger sections also have their own sound. Three or more trumpets create a lot of power in unison and can sound like a fanfare in block chords. Four or five French horns invoke a Nelson Riddle or Henry Mancini sound. The combination of four or five trombones is a compelling (if underutilized) sound — they can reproduce the warm, padlike quality of French horns, with more attack and edge for punchy, articulated passages.

For the most part, the exact configurations of the previously mentioned horn sections were not written in stone, especially in the recording studio. They often doubled parts (sometimes recording an additional pass, swapping the alto sax and trumpet parts on the lead line to blend the sound further) and added notes on certain chords (up to five- or even six-part harmony).

Several years ago I recorded Chicago's horns on a song for another artist, and their technique involved recording two passes. The first pass established the basic Chicago sound of unisons, octaves, and harmony hits; the second pass combined exact doubling, part swapping between alto sax and trumpet, and filling in the harmony on a few sustained chords and all of the short hit chords. (One of the players sketched the chart. The section executed it in exactly two passes, collected its checks, and left within 20 minutes.)

However, if you've ever seen Chicago — or any good band with horns — in a live setting, the three- or four-piece section holds up extremely well without overdubs. Even a small horn section has a visceral impact onstage.

Most important is good note choice — the key to making a horn section of any size sound great. Concentrate first on lead (upper) lines that work well against the main vocal melody and that center on a range appropriate for the arrangement's overall intensity level. Octaves and unisons, especially in the octave around middle C, always sound great and are sometimes all you need.

As a general rule, harmony parts filling in around the lead horn line should include the more important chord tones, such as the third, seventh, ninth, and so forth (see Fig. 2). Stay away from roots and fifths unless those notes are necessary for good voice leading or you are working with a larger section in which other parts already cover the upper chord extensions. An exception to this is the bari sax, which often reinforces the root of the chord as a stylistic effect.

Although open voicings (large intervals between parts) are an effective technique for string writing, horn parts sound much better with close voicings. Extremely close four- and five-part writing that moves a lot can sound very big band, but as a rule, don't be afraid to write close intervals. Most horn players have developed the ability to play tight voicings that even include seconds. Sometimes you can effectively separate the lead line a bit — say, a fourth or sixth above the rest of the horn harmony — to create some space for the lead to stand out.

With brass instruments, mutes can be quite effective. Also don't forget about the variety of special articulations. Horns can create unique and interesting sounds with scoops, slides, and flutter-tonguing — utilize those abilities to the advantage of your arrangements.

Composer and producer Rob Shrock is the keyboardist and music director for Burt Bacharach and has recorded or performed with Garth Brooks, Ray Charles, Elvis Costello, Sheryl Crow, Isaac Hayes, Faith Hill, and others.