Martin Russ looks at the evolution of Roland's approach to computers in music, culminating in their latest range of CM modules and accessories.

Roland have always had a clear and consistent approach to the use of computers in music. The 'industry standard' MIDI computer interface has always been the Roland MPU401, an 'intelligent' plug-in card for the IBM PC and compatibles (and Apple II originally) which appeared soon after the MIDI Specification. Unlike almost every other add-on MIDI interface, the MPU401 does a lot of the hard work of coping with the sending and receiving of MIDI messages and so frees the host computer from such tedious tasks, leaving greater capacity for sophisticated processing. In contrast, a typical Amiga MIDI interface usually contains a simple peripheral chip which sends and receives raw bytes, and requires careful monitoring and control software to be running on the computer for it to work correctly. In fact, many of the MPU401 'clones' produced by competing manufacturers (eg. Voyetra OP4001) actually utilise the Roland chip in their design (presumably under license?).

Before MIDI appeared on the scene, Roland had made use of their Amdek alter-ego to market a range of DIY effects boxes, along with computer monitors and an obscure and unimpressive music add-on for some almost as obscure computers: the Compu-Music CMU800. The CMU800 could be interfaced to the Apple II, the Sharp MZ80K, and the NEC PC8001. It looked more like a simple 4-channel mixer than anything else, although the large knob marked 'Tempo' on the sloping front panel was probably a good pointer to its real identity. The most important thing about this unit was the low price and the fact that it was, at the time, one of only a very small number of devices designed specifically for use with a computer.

What you might not know is that the Amdek range metamorphosed into a very successful range of Roland X-Y Plotters, which are widely used for plotting out graphical data throughout industry and commerce. Roland's consistent theme in all this is one of supporting a range of computers, and often leading the field.

COMPUTER MUSIC TODAY

The latest additions to this history of computer products are the Computer Music modules - a range of add-on devices designed for use with any computer that can be fitted with a MIDI port. By using a standard like MIDI, many of the problems traditionally associated with interfacing to computers can be neatly sidestepped, and so these CM modules can be used with Atari STs, Commodore Amigas, IBM PC compatibles, Apple Macintoshes, and almost any other computer. Continuing their association with PC compatibles, Roland have produced a special unit which combines an intelligent MIDI interface with sound generation circuitry for MSDOS users - and there's even a PS/2 MIDI interface for OS/2 users, too.

The word 'modules' gives away the difference between these units and Roland's more traditional synthesizer expanders - by my interpretation an expander has front panel controls and a module has none! Well, almost none: the rotary Volume control knob, Power on/off switch with red LED, and the contrasting green MIDI Message LED complete the survey of the front panel of the CM modules, which means that everything else is only accessible via software, or more specifically via MIDI.

And this brings up an interesting point - although designed for use with software and computers, one could conceivably use these modules with a master keyboard, which means that non-computer types should read on as well...

THE MODULES...

At the heart of all the modules in the CM range are essentially two different products: an LA unit very much like the MT32, and an RS-PCM unit rather like the U110. The three modules in question are the LA-based CM32L, the RS-PCM CM32P, and putting the two together in the same box gives the CM64. Let's look at each CM32 unit in turn, and then consider the CM64 in its role as a complete MIDI sound box.

LA SYNTHESIS

The MT32 is in many ways a very direct ancestor of the computer modules - it featured a minimalistic user interface which offered no front panel editing, only sound selection functions. What made the MT32 special was its extraordinary ratio of sound-making facilities for the price: 32-note polyphony, giving eight multitimbral parts with an 'LA Synthesis' sound very similar to the D50; a digital reverb unit; and a drum machine as well. When I reviewed it several years ago, I was knocked out by the combination of instantly usable sounds and affordability. Since then Roland's D110, D10, D5 etc, have all provided additional exploitation of the underlying 'sampled attack with synthesized sustain' Sample+Synthesis (S+S) technique, with the D110 providing improved sound quality and 'front panel editing' to the MT32.

The CM32L appears to be a repackaged MT32. The PCB inside has been reworked - the space for the RAM battery backup (never fitted to production MT32s) is now missing, and a headphone amplifier has been added. The quality of design and assembly is well up to Roland's usual high standard. The major difference is an improvement in the drum sounds - an additional 33 sound effects have been added to the 30 conventional drum sounds which already reside in the MT32 and D110. Effects is the watch word here, because you get a selection of sounds which seem to have been chosen to accompany computer 'arcade' games - there's a helicopter, machine guns, a scream, a train, a car crash, and so on.

As with the MT32 drum sounds, these effects sounds suffer from the same constraints: fixed playback pitch and the same reverb as the voices, although you can switch the reverb on/off and pan position for each key. A potential problem for master keyboard users is the note range which accesses these effects - they start at E5 (MIDI note number 76) and go up to C8 (108). This is outside the normal playing range of most five-octave keyboards, without resorting to octave transposition, although adding the odd clap of thunder or dog bark is unlikely to be a common occurence for most users!

The LA sounds themselves are the same as on the MT32: 128 preset sounds covering a wide range of genres. These sounds can be edited using a dedicated software package, and extra sounds can be downloaded via MIDI. Just as with the MT32, the actual number of different presets is less than the stated 128, since many of the sounds are actually just variations on the same sound but using different numbers of the constituent partials, and thereby providing different degrees of polyphony. The CM32L provides a maximum of 32-note polyphony from its 32 partials, assuming that each note uses just one partial. As you use more partials, this polyphony rapidly diminishes. With skillful arrangement, though, the final results can sound very full and rich, and the dynamic voice allocation always makes the most of the available polyphony, with the 'partial reserve' feature allowing you to prevent note-stealing from the most important parts.

LA's particular dialect of the S+S synthesis technique provides a good mix of digital and analogue-feel sounds, many with that 'synthetic but realistic at the same time' character that made the D50 so popular. The reverb used on the unit is not my favourite - it seems to have rather too much of a sense of slapback echo to it, but it is certainly a very useful treatment to have on-board for most purposes. The main problem with the MT32 and the CM32L is the discernible noise in the audio output - although a gating function keeps the output silent when no sounds are playing, the LA sounds themselves are accompanied by broadband noise which tracks their volume. The PCM drum and effects sounds do not seem to be as badly affected.

PCM SAMPLE PLAYBACK

The sounds produced by 16-bit PCM sampling give stunningly authentic and high quality playback of real sounds. The CM32P is a repackaged U110, a playback-only sampler with 99 preset sounds. The CM32P reduces the number of presets to just 64 but the same U110 Library Cards can be used in the slot in the front panel, so sets of additional 64 sounds can be accessed, giving a total of 128 altogether. The CM32P has one less partial than the CM32L, which reduces its polyphony to 31 notes instead of 32. The number of multitimbral parts is also reduced to six, and there are no drum sounds on-board, unlike the U110.

The digitised sounds inside the CM32P are a mix of orchestral and group requirements: Acoustic and Electric Piano, Acoustic and Electric Guitar, Slap, Fingered, Picked, Fretless and Acoustic Bass, Choir and String sounds, Electric Organ, Trumpets and Trombones, Saxes, Brass, and an Orchestral Thump. The sounds are multisampled where appropriate, and velocity switching and mixing are used to good advantage. As with any preset sample instrument, individual tastes determine whether or not you like the samples provided. For example, the pianos were a smidgeon bright for my taste, the acoustic guitars were all metal strung (I love the Emu Proteus nylon strung acoustic guitar!), and there were rather too many organ tones - but the trumpets were wonderful. Additional sounds are available on the U110 Library Cards: currently there are seven cards available.

The U110's chorus and tremolo sections, which offered something other than the global reverb usually found on expanders, have been omitted from the CM32P and replaced with reverb! [A sensible decision given the target audience for this product - Ed.] The output quality (quantisation noise on the reverb and decay tails) is not as good as that on the U20 and U220 units, which have recently been released, but it is still highly usable, and the range of tones complement the CM32L nicely. The combination is so good that it reappears on the CM64 - of which more soon. The CM32P provides audio sockets so that the CM32L can be connected to give a single mixed audio output.

Unlike the CM32L there is no MIDI Out socket, so all MIDI communication is strictly one way. The CM32P uses MIDI channels 11 to 16 for its six parts, which means that when using the Digital Fader (see below) you would need the channel assignments altering with a computer (remember that there are no front panel controls, so software has to be used to alter everything, except volume).

The CM32L and the CM32P are combined into one unit to produce the CM64. The MIDI channel assignments and number of multitimbral parts (14, plus drums) almost fill the available 16 channels, which makes one suspect that some careful forward planning went into the design of the MT32 and the U110. The result is a unit capable of rich analogue-type synthesizer sounds, realistic sampled sounds, and a mixture of the two. All this, plus a remarkable maximum of 63-note polyphony! The two separate reverbs offer the opportunity to try different types on the two sections, as well as different depths of reverb. This really is a versatile and capable sound unit, offering a comprehensive set of facilities in a single compact unit. For many computer music dabblers, it could be all they will ever need.

MODULE CONSTRUCTION

The computer-grey plastic boxes used on the three CM modules are heavier than they look, mainly due to the sturdy steel screening which is hidden inside. Connections are all made to the rear panel: MIDI In, Out (CM32P excluded) and Thru, as well as the stereo output jacks and headphone jack socket. Power is supplied via the usual Roland external power supply. Unlike the D110, U110 and U20, the RAM is not battery-backed and so all edits are lost on power-down, but this makes sense in a computer-based situation where the setup can be reloaded from disk.

The power is regulated inside the module using the screening as a heatsink - the modules do not seem to get unduly hot, even after long periods, and there are no ventilation holes to fill up with dust. The modules are designed to be mounted horizontally or vertically to suit the application. In traditional rack-mount terms they are about 3mm too high to fit into a 1U slot and 284mm wide - about 2/3rds of a 19" wide slot. Being specifically designed for computer use, the rack size compatibility is a bit of a red herring - the modules were ideal as a plinth for my Atari SM125 monitor!

PC SOUND CARD

In addition to the CM modules, Roland have produced the LAPC1 - a purpose-built, 'long' expansion card for IBM PC compatibles that provides the facilities and sounds of the MT32 along with an MPU401-compatible MIDI interface. The optional MIDI Connector Box (the MCB1) plugs into a 'D' type connector on the rear panel of the card. The extra sound effects described above are present on this card as well, which brings their intended purpose of acting as the soundtrack to PC computer games fully into focus.

Some commercial games programs already incorporate the necessary commands to drive the LAPC card, and this seems to be a growth area for the future - certainly the sound facilities of most personal computers leave a lot to be desired in comparison. Only the Commodore Amiga has the sort of integral features which would make add-ons like this redundant, so the potential market is huge. I have heard some very impressive music produced from a PC fitted with an LAPC1 card and running Dynaware's Ballade sequencer/editor program.

The MCB1 Connector Box itself provides MIDI In, Out and Thru, as well as a Metronome Output and Tape In/Out for synchronising to a tape recorder. The same box can be used with a PS/2 computer using the Micro Channel Architecture (MCA) bus format by installing Roland's MPU-IMC card, which provides just the standard MIDI interface functions. The MIDI Outs of both these cards could, of course, be connected to any of the sound modules already described.

ACCESSORIES

Once equipped with comprehensive sound generation capabilities, and some powerful sequencing software, the computer musician is faced with the problem of inputting musical data and controlling the system as a whole. The conventional hi-tech musician's approach would be to use a MIDI keyboard of some sort to provide notes, chords and controller information, plus a mixer to control the audio signals, but this stresses the performance aspect and hardware side of hi-tech music in a way which is not necessarily required in computer music.

So, to complement the CM modules, Roland have applied the same ideas of tailoring products for a specific application area and produced a series of Computer Music peripherals. The three current models are the Digital Fader, the Music Entry Pad, and the Intelligent Arranger. These can be used with the CM modules and a computer, or could form part of a more conventional keyboard rig. All three low-profile, sloping, computer-grey plastic units are constructed using membrane-type switches as part of the top surface of the pad, and one pad will fit neatly on top of any of the CM modules.

DIGITAL FADER

The CF10 Digital Fader is a replacement for an analogue audio mixer. The 10 fader areas are permanently assigned to MIDI channels 1 to 10 and send MIDI Volume messages (Controller number 7) to the rear panel MIDI Out socket whenever they are pressed. Fine-tuning buttons provide incremental control over volume-pressing the fader areas themselves is not very accurate or repeatable, as they are really only coarse controls for rapid setting up of levels. There are also separate incremental pan controls for each channel, using Controller number 16.

The unit is designed to interface to modules like the CM32L, where the MIDI channels fall into the correct range (the CM32P uses channels 11 to 16 as its default) or with software where the faders can act as channel volume controllers. The MIDI In and Merge on/off switch on the rear panel mean that the pad can be used 'in-line' with other controllers, like master keyboards or even the CN20 Music Entry Pad...

MUSIC ENTRY PAD

The CN20 Music Entry Pad is specifically designed for entering music data into software. It provides a 22-note keyboard which can be scaled over a seven octave range, thus generating MIDI note numbers from 0 to 127. The right-hand slider control governs the Velocity of the Note-On messages, whilst the other slider can be used as a MIDI controller for Controller numbers 16 (not used in the CM modules described here), 10 (Pan), 7 (Volume) and 1 (Modulation), as well as act as a Pitch Bend and Aftertouch control. Clever use of the LED indicator involves blinking when the slider position is non-zero, with the blinking stopping when the 'zero' position is reached - this means that no detenting is needed on this multipurpose control.

A separate mode allows chords to be sent with the pressing of only two switches, in a way very similar to the 'root and type' system used on auto-accompaniment organs. Program Changes, Hold messages (Controller number 64) and a MIDI Channel selection mode complete the front panel facilities. The rear panel features MIDI In and Out sockets, with a Merge switch to allow the pad to be placed 'in-line' with other controlling devices. Overall, this is a compact and easy way to enter music data into a personal computer without the expense, size, or complications of using a master keyboard.

INTELLIGENT ARRANGER

The CA30 Intelligent Arranger takes the concepts behind the E20 Intelligent Keyboard, the Pro-E Intelligent Arranger, and the RA50 Real-time Arranger and puts them into a pad which employs the same membrane switches and overall design as the Digital Fader and Music Entry Pad. The CA30 is designed to work with the CM modules and computer software, and takes a simple melody and chord progression and converts it to a more complex and intricate arrangement, complete with bass patterns and drum rhythms. 48 preset 'Music Styles' can be selected, with additional ones available on Style memory cards (compatible with the RA50, Pro-E, and E20: seven cards are currently available). All the traditional functions of an auto-arrangement device are provided: sync-start, fill-ins, breaks, variations, and auto-melody and chord sensing.

Unlike some similar arrangement devices, the Roland auto-arrangers have a marked feel of particular songs - I happily spent some time trying to work out where the influences for the melody and chordal rhythms have come from; the Rock 1 style bears close resemblance to some recent Genesis songs, for example. This can be both an advantage and a disadvantage, but for the user who wants to quickly create professional-sounding arrangements from simple ideas, then the CA30 may be exactly what is needed to make it happen!

MONITORING YOUR PERFORMANCE

Roland have adopted a complete systems approach - you can build up an entire computer music system where only the computer will be without a Roland badge! With this in mind, the Roland MA12C Micro Monitors are the ideal way to listen to the sounds produced by the Computer Music modules and peripherals.

The MA12C provides a high quality 10 watts RMS output into a 10cm full-range speaker housed in a compact cabinet (132 x 218 x 165mm), which weighs 2.5kg. The speaker magnet is shielded, although you should still be careful when using it near computer discs and TV monitors. Tone controls for high and low frequencies, together with a volume knob and on/off switch, provide the front panel controls, and a captive mains lead provides the 28 watts of required 240V power on the rear panel. Input jacks provide Microphone (-45dBm into 1 kOhm), Instrument (-15dBm into 50 kOhms) and Line (-15dBm into 50 kOhms) level inputs.

VERDICT

Roland's on-going commitment to the use of computers in music continues with these new products. As usual they are of high quality and well designed, with built-in musicality and good support in the form of sound and style memory cards. On the downside, there really does seem to have been a marked improvement in audio quality between the MT32/U110 and the D110/U20, where the latter models have a much less 'grainy' or noisy output. It is therefore somewhat disappointing that the earlier units are the ones to have been recycled into the CM range - but the lower pricing probably reflects this in the customer's favour!

For the computer enthusiast with an interest in music, this series of units could prove to be invaluable. Even the (jaded?) hi-tech musician may find that careful choice may produce a bargain to fill a gap in sound generating power - the 63-note polyphonic/14-part multitimbral CM64 being particularly attractive. So Roland's motto of 'We design the future' continues - watch this space for further developments...

FURTHER INFORMATION

See separate panel for prices.

Roland (UK) Ltd, (Contact Details).