Classic Computer Magazine Archive CREATIVE COMPUTING VOL. 10, NO. 5 / MAY 1984 / PAGE 68

The Roland Compu-Music 800. (evaluation) John J. Anderson.

The Roland Compu-Music 800

Flip on the radio to any pop, rock, or contemporary classical music station, and you'll hear it. You may like it, you may hate it, but you can't deny it: electronics have changed the sound of music.

It started with the advent of the electric guitar back in the 1950's. A lot of sneering went on. But rock and roll was born. Then the Moog synthesizer showed up in the late '60s. More sneering occurred. But so did Switched-On Bach.

In the 1970's, a new crop of multivoice sound synthesizers gained acceptance by the mainstream of pop, rock, and new wave sound. Sneer if you dare. And by the onset of the 80's, inexpensive computerized musical instruments had brought a new musical possibility to Joe Consumer: the idea of making his own music.

And as far as we are concerned, that is a major transition brought about by micro-processor technology. It has to a degree made obsolete passive entertainment, in favor of the interactive variety. You may become the rock star (or for that matter quarterback, artist, detective, race car driver, spy), instead of remaining a mere spectator. In short, you may be the programmer rather than the programmed.

Blinded Me With Science

Music machines now retailing for $500 and less can make Joe Consumer sound like Joe Jackson. As an alternative to listening to the radio, spinning a record, or watching MTV, you may opt to create your own noise--and make that noise sound pretty darned good. Preset drum patterns can help keep you on tempo. Automatic chord memories can provide the backup. LED indicators can tell you which melody keys to press. And if you need more help, some machines will read bar-coded scores directly into memory, for playback with or without your lead.

Now let's say you already know all this, and have an Apple Computer. You may take the reverse approach: adding a musical instrument to your computer. This potential has been around for a while. There are the Mountain Music System, the Alf, the Soundcaser, alpha Syntauri, and about a half dozen other music peripherials. And now there is a new contender from the makers of one of the most popular lines of professional synthesizers around: Roland.

Band In A Box

We wish you could play this magazine, to hear the Compu-Music 800 in action. Five hundred dollars is a small price to pay for your own band. The technical description up ahead does little to convey how good the unit sounds. With it, you have the basis of unlimited sound production of a quality that a short while ago would have required a small recording studio. If you already have a multitrack tape deck that allows recording of one channel during playback of another, all you need is a mike and a CMU-800, and you will have a small recording studio. If that is the kind of thought that excites you, do read on.

As opposed to other hardware that has come before, the CMU-800 is a self-contained stand-alone snythesizer that interfaces to the Apple through a card in slot 5. Run the disk accompanying the unit, and you are off.

The unit consists of six internal components:


Take It From The Top

Across the top of the CMU-800 are eight LED indicators, corresponding to the eight simultaneously available sound channels (refer to Figure 1). Channel one is the melody channel, two the bass channel, with a sound very much like an electric bass guitar. Channel three is the ehord channel, piping voice channels three through six, which are individually programmed, for output as chords. Channels seven and eight have no internal sound sources, but are used to control external inputs.

Below and in line with the LEDs are separate decay controls for melody, bass, and chord channels. These control the amount of time it takes for a note to fade away after it sounds--like holding down a piano key after it is struck. In addition, the melody channel has a sustain control that allows for a slightly longer held ring. This helps the definition of the melody line. Below and in line with these are the slide controls for output volume.

On the righthand side of the unit is the tempo knob. The tempo is simply the rate at which music is played, and it can be set any way for any piece. It can even be changed while music is playing.

Bringing Up The Rear

On the rear of the unit are varied input and output jacks (refer to Figure 2). These include a mix output for all audio channels, and separate outputs for rhythm, chord, bass, and melody. A pulse signal from the internal clock oscillator is available from the clock/out jack, and an external clock pulse can be attached using clock/in. For the control of ternal synthesizers, eight gate pulse, and control voltage jacks are available. Using these, the CMU-800 can access and program up to eight external synthesizes.

The Well-Tempered Apple

Most of the musical instructions to be sent to the CMU-800, however, do not come via the control panel or external patch connection. Enter the Apple II, II+, or IIe with disk drive. The Apple software supplied with the unit, while not the most elegant program we have ever seen, is relatively easy to use, and provides the ability to squeeze the most out of the hardware.

Once the program is booted, the main command menu appears. This allows you to load, clear, save, verify, or edit music files. An added and extremely flexible feature allows you to transpose the key of an entire piece by half-tones up to two octaves in either direction.

Loading a pre-existing music file is as simple as typing L on the main menu screen. The program will then prompt you for a filename, which always uses the extender. CMU to distinguish it from other sorts of files. When the main menu returns, the file has been loaded. After hooking up to an external amplifier, press P, and you'll hear the tune. You can stop it and start it wherever you like, or play it continuously.

To begin creating your own sound, you enter the editor. The editor considers only one sound channel at a time, and allows you to see exactly how each is programmed. By typing E while listening to a piece, you can go in and edit at the point of the last note heard. Through the editor, you enter the codes that correspond to the musical values you desire.

Carrying The Tune

This is where things start to get a bit sticky, but compared to other systems we have seen, Compu-Music does pretty well. Each note entered is automatically given a value by the computer, called its "step number.' As in traditional musical notation, data are divided into measures. While it is not essential for the computer to delineate measures, it is certainly essential for you--to keep timing organized across all channels. As the end of each measure is indicated, the computer automatically advances to the next. Then when problems arise, they can be clearly pinpointed and corrected measure by measure.

For pitches to be entered into the CMU-800, they must first be translated into numbers the computer will understand. Unfortunately, the current release of Compu-Music software, like most Apple products that have come before, requires "wet' memory fot this task. This means you do the translation with your brain. (For an alternative approach, see the review of Music Construction Set in an upcoming issue.)

Don't get the wrong idea--it is not all that tough. Each note of the scale is represented by a number. The lowest C is 0, C sharp is 1, D is 2, and so on to 112. Because there are twelve notes in an octabe, the first C above the bottom is 12, the second 24, ad nauseum. According to the documentation, "it is a good idea to just memorize the CV (control voltage) values.' Not bloody likely. Here at the lab, our brain buffers are already too full of deadline dates, point spreads, phone numbers, and cryptic command codes to allow other machines to demand that kind of an effort. Luckily, the appendix provides a complete chart of values.

Note durations are also represented by numbers, called "step times.' This range must be between 1 and 255. The number that is chosen to represent a quarter note is called the "time base.' A time base of 24 is highly recommended, as it is evenly divisible by three or four. This makes eighth, sixteenth, and thirty-secondth notes, as well as triplets, easy to effect.

In electronic music, and the CMU-800, the articulation of a specific note is called the "gate time,' and is also represented by a numerical value (in this case between 0 and 255). This corresponds to the length of time the "keys' are held down. It functions relative to step time; gate time may never exceed step time for a single note. However, a note with a relatively long step time and a relatively short gate time will sound staccato during articulation. If the gate time is set to zero, you have created a rest. According to the documentation, "gate time allows the computer to gain a sense of "human expression' which would be sorely missed if it were not available.'

Tonal music data for the Compu-Music consist, therefore, of lists of values across measures of pitch, step, and gate. Getting chunks of these to mean much to you from the editor does take a bit of practice. But because you can listen to whichever parts of the composition you want, zeroing in on problems is facilitated.

Beating The Drums

The percussion potential of the CMU-800 is one of its most attractive features. Using the seven-voice drum synthesizer, rhythm patterns of nearly any style and complexity can be attained. Though it might not fare so well with Bach, adding a rhythm channel to a pop- or rock-style composition really enhances its sound.

Rhythm patterns are set up in channel 0 and are then called into the score by channel 9. A pattern consists of a single measure. Which is broken into 16 steps across the seven available percussion voices. To "hit' the bass drum, type an X under the B column in channel 0. An example is shown as Figure 3. This plays a bass drum quarter note on each beat of the measure; notice that the total step time for the pattern is 24. Using the keys A for left, S for right, W for up and Z for down in the editor, you can move the cursor around the pattern grid, putting in the percussion "hits' you desire. Typing a period over an X cancels it. Figure 4 shows a simple waltz pattern on the bass and snare. Each "hit' is a beat. Because the step time in the far right column has been set at zero after the first three rows or beats, they will be skipped entirely.

Rolls, flams, syncopation, and other percussion effects can be created easily using drum pattern grids. Most pieces will use a multiple rhythm "library,' repeating old patterns and invoking new ones as desired.

Know Your Editor

The final hurdle in working with the Compu-Music unit is learning the shortcuts. The editor has been designed to eliminate busywork wherever possible (a partial list of commands appears as Figure 5). As with a word processor, musical data can be inserted, altered, or deleted without much effort. The copy function allows data to be copied without tedious retyping. If a phrase is to be repeated, the copy function makes it simple. When creating chord progressions, the copy function is indispensable. After ironing out the first channel for a chord, copy the lead chord data right into the next chord channel. Then change only the pitch data to finalize the second voice of the progression. This process can be repeated for the remainder of chord channels.

Symbiotic Synthesizers

The Compu-Music also has the ability to control up to eight voices of external snythesis through the outputs of its back panel. The only requirement for hook-up of an external synthesizer is that it accept control voltage inputs and be set at one volt per octave, which is standard. It is also possible to combine internal and external voices for a much "fatter' sound.

Keyboard synthesizers from Roland and other sources can be controlled by an Apple through this means--and programmed in exactly the same way as the Compu-Music unit itself.

The Down Side

There aren't very many criticisms we can level at the CMU-800. The ones that do come to mind are softened by ear--as stated above, once you hear the potential of the machine, you just want to sit down and start working with it. Still, we can be picky: that is our job.

The software could be better. It wouldn't take all that much to do the translation from musical notation to numerical codes inside the Apple. This would make for a much friendlier device. According to Jeff Rona of Roland, work is underway on a new release of the driver software that will offer an improvement on that score. As it stands now, the Compu-Music is a much greater hardware than software achievement. But that is a much better situation to be in than the reverse, which is where many other Apple music peripherals stand--nice user interface, but short on the hardware side.

The documentation puts it well: "Unlike anything available before, the Compu-Music is an open-ended system. Other electronic instruments. . . cannot be changed without expensive modification or replacement . . . With Compu-Music, the hardware is just the beginning. It is only half the system. New software can be created for various applications to allow the system to continually grow.'

It is rather unfortunate that the waveform envelopes are preset for all voices. Perhaps this is too much to hope for the price, but it would have made the Compu-Music a much more attractive system. The Compu-Music can, for course, be used with external signal processors to enhance its sound. The sound can be modified with equalizers, flangers, phasers, echos, reverbs, filters, wah-wahs, delays; you name it. The full mix can be modified, as can individual channels.

Not to say that the preset envelopes are not acceptable. They are really quite nice, as is plain vanilla ice cream. Wouldn't it have been fantastic, though, if just a few voice effects were available from within the unit itself?

The documentation leaves a bit to be desired. It is short, sketchy, rife with typos, incompletely glossaried, and totally unindexed. It could have done with more examples and has the feel of something hastily translated from a non-Indo-European tongue.

Still, enough information does appear in it to get you going.

Bozos Beware

A caveat. Whatever you do, make sure you plug the interface card for the unit in correctly. In what we see as an unfortunate decision, the connector card for the CMU-800 has the same Apple-slot-style edge connector on both ends. Despite the fact that the card is well labeled, and the component side would have to do an about face, this raises the ugly possibility of hooking up backwards. As Murphy's Law applies nowhere more religiously than here at the lab, a former editor who shall remain nameless did just that, blowing out our initial review unit in the process. (As we heard at CES after the incident, the mere mention of this nameless editor's name at Roland induces seizures.)

So, if you are as dumb as we are, be extra careful. The potential is there for a fatal screw-up right out of the box.

On the dream list, a real-time keyboard peripheral a la Soundchaser would bring the Compu-Music into the major leagues. Admittedly, this would change the whole direction of the machine. For now, we'll be content jamming in real time on a Casio 401.

The Tag

Nit-picking aside, we rate the Roland Compu-Music at $500 as a next-generation breakthrough in microcomputer controlled music synthesis. Let me confirm it: some of you who have just read this now have found the system you have been waiting for. Roland has announced that interfaces to other popular micros will be available soon. So get out there and hear one!

Figure 5.

1. By typing the MEASURE and STEP number, the cursor can be moved to any point in the score.

2. I --INSERT--Allows for inserting and adding data anywhere in the music.

3. D --DELETE--Allows for deleting any amount of data.

4. C or . --COPY--Data already entered can be copied and used anywhere in the piece without being retyped.

5. M --MEASURE PLAY--Plays only the measure the cursor is in. Allows for rapid error checks.

6. P --POINT PLAY--Plays the entire piece starting at the cursor point.

7. = --SOUND EDIT--Plays the pitches as they are entered.

8. ? --HELP--Displays all the edit commands on the screen.

9. F --FORWARD PAGE--Moves the editor ahead one page.

10. B --BACK PAGE--Moves the editor backward one page.

11. T --TRANSPOSE--Allows for changing of CV bias (key) in any section of the music.

12. esc --QUIT--Leaves the section of the editor being used. Hitting the esc key also stops music if it is playing.

13. < > --REPEAT--Lets any block of notes be repeated multiple times.

Table: Figure 3.

Table: Figure 4.

Photo: Figure 1. The top of the Compu-Music 800 includes a mixer for the band in the box. Linear controls make setting channel output volumes precise and easy.

LED's above each channel control indicate which are currently being used. Tempo knob, on far right, can be adjusted on the fly.

1) LED indicators

2) decay controls

3) audio output mix:

A--melody channel

B--bass channel

C--chord channel

D--drum channel

E--master volume

4) protamento knob

5) tempo knob

6) tuner plug

Photo: Figure 2.

1) power switch

2) audio outputs:

A) mix (all channels)

B) rhythm

C) chord

D) bass

E) melody

3) clock in/out

4) ribbon cable to computer

5) eight gates for connection to external synthesizers

Products: Roland Compu-Music 800 (synthesizer) - Evaluation