Multi-Track Recording Building a Studio Production


Most of the music commercially recorded in a studio today, even classical and acoustic music, is multi-tracked. Each instrument is recorded on its own separate track or tracks, sometimes dozens of simultaneous tracks. All of these tracks are then blended, or mixed down, into a two-track stereo recording suitable for putting on a CD. ("Stereo," or stereophonic, means two independent tracks. It's the reason your stereo has two speakers, and it's been the standard for commercially distributed recordings since the 1960s.)

Putting each instrument on a separate track allows precise adjustment of each instrument's volume, tone, and other qualities during mixdown. It also gives the engineer and musicians the luxury of optimizing the final balance over a period of time, rather than having to live with decisions made on the fly during the performance.

Alone in a Crowd

Sometimes these individual tracks are created simultaneously, while the whole ensemble plays at once. Separate microphones or inputs are used for each instrument, and each is recorded to its own track. However, adjusting each instrument separately at mixdown time requires good isolation between tracks.

For instance, let's say that the guitar player and the banjo player are standing next to each other while they record. Even if each has a separate microphone, the banjo part will be picked up by the guitar mic and vice versa. So anything done to the guitar part during mixdown will also affect the banjo part.

Solving the Problem

There are a couple of ways around this problem. In a larger studio, there may be separate rooms or isolation booths. Or sound-absorbing baffles can be placed between players. Even so, the sound isolation may not be perfect, and communication can be hampered if players aren't next to each other.

Another solution is to record each instrument, or group of instruments, one at a time. The musicians play along to tracks already recorded, while listening through headphones. This has the advantage of providing perfect isolation, and thus the ability to go back and re-do any individual tracks without affecting the rest of the recording.

The drawback is that some of the interplay between musicians can get lost when they don't all play at once. Also, learning to lay down an inspired performance while listening to the rest of the band through headphones may not be easy at first, and some players don't like it much.

However, if the musicians can adjust to this approach, the recorded sound will usually be of higher quality, since the sonic compromises that happen when a whole bunch of people play all at once in the studio can be avoided. It's also the most flexible way to work. Each player can do multiple takes until they get their part the way they want it. Furthermore, it allows editing, or even combining the best of several takes, for each individual part. And it makes it much easier during mixdown to get the blend of one part with another exactly right.

Who's On First

There's another issue when tracks are laid down one at a time who goes first? Usually rhythm instruments are the best to start with, assuming that the rhythm players can lay down their parts perfectly while playing all by themselves. Often a "click track," like a metronome, is used to keep the beat steady. Again, these kinds of studio skills are a bit different from live performance skills, and may not be easy for some musicians.

Scratch My Track

Another approach is a "scratch track." In this case, everybody plays the song all at once, and it's recorded without worrying about isolation. Then, while listening to this scratch track through headphones, each musician lays down their own part separately. This has the advantages of preserving a live feel, and providing a full sound in the headphones for laying down individual tracks later. At some point, the original scratch track may be discarded.

Another possibility, especially if the song has a steady rhythm and well-defined parts (verse, chorus, etc.) is to build a scratch track using MIDI software. Depending on the song, it can be easy and quick to build a computer-generated arrangement, complete with bass, drums, keyboards, guitar, etc. It can sound amazingly realistic for a computer. Granted, it may be too artificial to use in the final product, but it makes a great scratch track with a rock-steady beat, and allows easy replacement of each "robot" part with a human being, one at a time. And the computer-generated tracks can be edited, and some may be good enough to keep. This approach is particularly suited for songwriters making a demo, or multi-instrumentalists who want to record a "one-man band."

Studio Wars

Now that the computer is making more and more inroads into the recording studio, the concept of multi-tracking, which is really a linear model based on the tape recorder, is giving way to the "word processor" approach to music, where snippets of sound can be cut, pasted, and moved around at will. This means that the old question of "How many tracks does your studio have" has become irrelevant. A studio equipped with a typical modern computer can create as complex a production as you want.

It also threatens to let the technology take over the music if you can assemble a great performance with your mouse, what happened to the art of performing? The challenge is to use your powers for good and not for evil. May the force be with you.

Trick or Treat

Obviously, out of the vast range of possible techniques, choices have to be made that will best serve the song or music being recorded, the artist, the budget, etc. Often a naturalistic approach works best, and can be the easiest and most straightforward for the performers. For many projects, though, using a wider palette of studio techniques can provide a fuller, more dramatic sound. Believe it or not, almost anything you hear on the radio or buy on a CD uses these tricks all the time.