The 2004 release of GarageBand by Apple was a significant breakthrough in audio sequencing. The program is noted for its friendly interface, integration with iTunes, and attractive price (free for those who buy a new Apple computer). GarageBand opened the door to composing and arranging for Mac-based music students who could not (or would not) learn to notate music in the traditional manner.

After a little practice using the program, anyone (especially the youngest, most computer savvy) can now create an original musical score that can be played back on the computer. Perhaps music constructionist is a more appropriate term than composer, arranger, or performer here — instead of producing the primary sounds or ideas in the conventional manner, the music constructionist takes processed materials, such as prerecorded sound loops or MIDI audio tracks, and assembles them digitally to create a musical work.

FIG. 1: Searching for “mozart clarinet concerto” on Google yields more than a million sites.

This is the most popular use of GarageBand, and it has sparked a certain amount of controversy. On one hand, you may be a cutting-edge innovator blithely forging ahead without the least bit of training in notation or even in traditional performance practices. GarageBand has freed your creative impulses (and maybe even made you millions of dollars) without shackling you to the tedious lessons and hours of practice required to be an old-school musician.

On the other hand, you may be a hard-core purist denouncing DJs, remixers, and other music constructionists as amateurs and infidels. For you, GarageBand is one more sinister ploy, seeming to bring music closer to more people while actually bringing us all closer to the day when only robots will know the special joy that comes from playing real instruments!

Of course, between these two extremes stand millions of music students of all ages, skill levels, and musical tastes. Many seek out teachers to help them learn how to play their instruments, and quite a few supplement these face-to-face lessons with so-called music-minus-one recordings, which allow them to practice or even perform on their own with a prerecorded accompaniment. GarageBand can help this endeavor in ways that may not have been intended by its inventors, headed by Dr. Gerhard Lengeling, formerly of the German company Emagic.

Since version 2 was released in 2005, GarageBand has allowed users to easily import MIDI files. As you probably know, MIDI is a digital protocol that sends musical performance information between computers and electronic musical instruments, and it's the basis for millions of free music files in many genres that can be found all over the Internet.

Using GarageBand, you can create personalized music-minus-one files for free (that is, free after you've bought the computer and paid for Internet access). Once you import a MIDI file into the program, you can adjust it to any tempo and key. By utilizing the sampled instruments available in GarageBand and various GarageBand Jam Packs (optional sample libraries), you can produce a song of considerable quality.

Students can play along with the files and also record themselves at the same time. They can use this approach to produce audition tracks, test themselves, and share with fellow students. Teachers can use this system to create homework projects and even monitor a student's progress from faraway places (like when you are on vacation in Hawaii!).

FIG. 2: Limiting the search to “"mozart clarinet concerto" + .mid” narrows the results to only those sites with MIDI files of the composition.

Unfortunately, like so many of Apple's best products, GarageBand is available only for Macintosh computers. PC programs like Sony Acid Pro or any other sequencing software can function like GarageBand, but it's more complicated. Music-notation programs like Sibelius and Finale can also be adapted for music-minus-one applications, but without the ease of use that is such an Apple hallmark.

Making a music-minus-one recording in GarageBand requires a few basic, happily uncomplicated steps. The first step is simply to get familiar with the program. It employs an intuitive interface based on drag-and-drop operation with icons in the main window and little need for menu access. Apple offers a helpful tutorial at www.apple.com/ilife/tutorials/#garageband.

The next step is to find and download the MIDI files you want to use. To illustrate this simple process, let's use Mozart's Concerto in A Major for clarinet and orchestra, K. 622, a very popular piece for clarinet students.

A simple search on Yahoo or Google for the phrase “mozart clarinet concerto” results in myriad pages (about 1.15 million sites on Google), including audio recordings, sheet music, and various YouTube performances (see Fig. 1). To narrow the search to MIDI files of this piece, search using the string “mozart clarinet concerto“ + .mid. This yields only MIDI files of that work (about 12,000 sites on Google; see Fig. 2). Once you find an appropriate site containing the file, simply download it to your desktop; on the Mac, press the Control key and click on the link.

Next, listen to the file to make sure it is actually what you want. Quality can vary widely, and a piece that was composed for multiple instruments may have wound up as a MIDI file of a solo keyboard performance or, even worse, an annoying ringtone. Sometimes MIDI files cut off in funny places and don't give you the complete work. To minimize frustration, it always pays to check the file before moving on.

The next step puts GarageBand and the MIDI file together. First, open GarageBand and create a new file. Let's name it “Mozart Clarinet Concerto K622.” (Hint: be careful about naming your files so you can remember what they are and what you are using them for. I learned that one the hard way.)

To import the MIDI file into GarageBand, drag the file from the desktop into the Region window (see Fig. 3). Once the file is dragged into position, GarageBand automatically assigns instruments to each MIDI track.

GarageBand does a great job of assigning appropriate instruments for each track, and the sampled sounds that come with the program are acceptable in quality. For those who want even higher-quality sounds, the five GarageBand Jam Packs are a worthwhile investment (see Fig. 4). The Symphony Orchestra Jam Pack contains a large selection of symphonic instruments, including a realistic-sounding orchestral Steinway piano. Other Jam Packs include Rhythm Section, World Music, Remix Tools, and Voices. Each Jam Pack sells for about $100.