Roland's TR707 has been a big hit in the digital drum machine stakes. Now a sister instrument, the TR727, adds Latin Percussion sounds to the company's vocabulary. If anything, it raises the standard further.

In industry, you can't keep a good idea quiet for long enough. You can do what you can to protect it against industrial espionage while it's still in the development stage, and in that you might be extremely successful. But as soon as you launch an innovative product of mass appeal, it's an odds-on certainty that your competitors will have something similar on the stocks within a few months.

This is what Korg have found, anyway. A year ago, they launched a digital drum machine - the DDM220 - that went beyond the confines of conventional 'kit' drum sounds by offering a range of less common Latin ones instead. The ordinary rock drum kit is far from dead, of course, so the company released a 'traditional' model, the DDM110, at the same time. But it was the 220 that musicians really took to, not least because for the first time, they had a means of introducing sonic variety, not just the rhythmic kind, into their programmed drum patterns.

Back in Japan, Korg's arch-rivals Roland looked on aghast at the success of the little box of Latin tricks, and promptly set about designing a competitor.

Well, that isn't strictly accurate, because the machine they came up with, the TR727, isn't a direct rival for the DDM220. What sets the two apart from the outset is price. Whereas the Korg costs only a little over the £200 mark, Roland's newcomer is an altogether more upmarket device, with an RRP of £550.

It has a complement of upmarket features, too, like separate audio outputs for each voice channel, MIDI In and Out sockets, a cartridge storage facility, and an excellent liquid crystal grid display that makes pattern programming and editing a lot easier.

Like a large part of the 727's specification, that display is identical to the one on the TR707, Roland's kit-drum digital percussion machine. So, the new addition comes replete with 15 digitally-sampled percussion sounds, sequencing software that allows programming in both step and real time, a rhythmic hierarchy that involves the user in Measures, Patterns and Tracks (in ascending order of length), and the useful niceties just mentioned.

I need hardly tell you that Roland have had more experience in producing programmable drum machines than just about anybody. Their first was the CR78 Compurhythm, a preset device that had pattern-programmability tacked on as something of an afterthought. But in spite of employing an incredibly unwieldy programming system, the machine was usable, and it offered a vast range of (analogue) drum voices, from standard snare drums to more unlikely things such as bongos and maracas - just the sort of voicing, in fact, that Roland are offering again with the advent of the TR727. In the intervening period, the company concentrated on 'ordinary' drums, and produced some machines (the TR606 and TR808) that were as musically influential as they were economically accessible.

Early last year, Roland announced a successor to the 808 in the shape of the TR909, but by that time, its analogue sounds were wearing a bit thin in the face of increasing digital competition. In the event, it turned out to be little more than a stop-gap model, now being sold at what can legitimately be described as bargain prices.

It was the TR707, unveiled towards the end of 1984 but already a huge success across the globe, that signalled Roland's return to the drum machine fore. The reason for its success? A combination of some excellent digital sounds, and a programming system derived from that used in the 808 and 909 — and which was therefore familiar territory for an awful lot of musicians.

So now that Roland have followed up the 707 with a Latin Percussion variant, is their drum machine range unbeatable? In the strictest terms, yes - they're the only company offering upper-range, professionally-specified machines of both rock and Latin varieties in self-contained packages. But getting your hands on the Roland pairing is an expensive business, largely because of the amount of hardware and software duplication that exists between the two.

Now, if Roland were to follow the lead taken by the Americans (notably Sequential, E-mu Systems and so on), they'd be able to offer a standard, dedicated drum machine for which additional sounds could be purchased at a later date and added to the overall system - that's a much more cost-effective way of doing things. But that's something they seem reluctant to do at present, which leaves musicians with the unpleasant prospect of having to buy another load of knobs, switches, sockets, displays, and sequencing software when all they want is relief from standard bass-and-snare backbeats.

But enough of this petty criticism. The TR727 sounds brilliant. Better than the DDM220 (which you'd expect, of course), and probably better than the TR707, seeing as its samples suffer less in the way of quantisation noise and cutoff problems than those on the earlier, rockier version.

"Sounds: Best of the bunch are the congas: all three of them are deliciously realistic... a real ear-opener."

The bongos are smooth but forceful, the timbales nicely low-tech and rootsy, and the agogos crisp and delicate, though curiously, they lack sparkle by comparison with those on the DDM220. As for the referee's whistles that seem to dominate most of Roland's demo patterns, they sound pretty good too — though I can't see you're ever going to need three of them, especially when two are identical.

Best of the bunch are the congas, though. The 727 gives you three - a low one and a higher-pitched one in both muted and open varieties - and they're all deliciously realistic. If you're used to the drifting, half-hearted analogue congas on the TR808, these'll be a real ear-opener.

Part of the reason for the 727's sonic success lies in the fact that a lot of LP sounds aren't all that demanding in terms of sample length and bandwidth. When it fails, it does so because one beat of the instrument being recorded either lasts too long or has too wide a frequency response for the 727's digital memory to accommodate. Biggest offender here is the star chime, a voice of novelty and appeal that cuts off very abruptly. You're probably more familiar with it in real life as a mark tree, and it isn't the only oddly-named voice on the Roland's front panel. The other is the quijada, which sounds to me like an excellent recording of a vibraslap. Still, the former word is probably the more historically accurate.

No problems with the last two voices, though. In most people's percussion language, cabasas and maracas are just that, and when they're recorded by Roland and stored digitally within the TR727, they sound uncomfortably close to the real thing, too.

Apart from the differences in voicing and a new colour scheme that sees the 707's trad orange replaced by a pleasant mid-blue, there's little difference between the two machines. Where the 707's spec lets it down, the 727's does likewise. And where the 707 is brilliant, the 727 is equally praiseworthy.

Briefly, the good points are the LCD graphic (with the exception of Simmons with the SDS6, Roland are the only company to have achieved something as detailed without resorting to an external computer), a well-specified rear panel, and a versatile programming system that lets you combine real- and step-time recording within the same pattern. The sockets that really make the difference are MIDI In and Out, which receive and transmit the MIDI clock as well as allowing you to play/program the 727's voices from the keys of a MIDI keyboard; tape sockets that let you save patterns to cassette and sync the machine to a clicktrack on a multitrack tape recorder; the Roland-standard Sync 24 connector that lets you marry a 727 up to a more aged device like an 808 or 606; and the individual voice outputs already mentioned. There's a fair bit of debate currently circulating round the industry's system as to the value of separate outs for drum voices. Personally, I reckon they're priceless. If there's a couple of sounds that need a bit of tweaking, no amount of onboard facilities is going to give you the width of options provided by a well-loaded 19" rack. By comparison, a built-in overall stereo output (such as that provided by the 727 and a lot of other machines in the same price category) isn't nearly as worthwhile, since if you've got the facility to reproduce sounds in stereo, chances are you're able to route them individually through a mixer as well, panning them, EQing them, and putting them through outboard effects units as you go.

What does the new Roland do badly? Not much. Its main drawbacks lie not so much with what it does, but with what's been omitted from its specification. Certainly, its programming facilities lack the imagination of something like Sequential's TOM, and it doesn't offer anything like a reasonable amount of voice-adjustment features. You can't tune the pitch of individual voices, and neither can you apply voice-selective accenting — there is an accent facility of variable degree, but if you apply it to a certain beat, all the voices programmed on that beat are accented by that degree.

Opinions vary on the user-friendliness of Roland's programming system. If you're used to it, the LCD window of the 727 will make life easier still. If you aren't, you might find it takes a bit of time before you're really writing patterns freely.

One related problem (and one that took me by surprise) is that programming Latin rhythm patterns isn't nearly as straightforward as performing the same job on a rock machine. Most people have some regular method they adopt when programming a rock drum pattern: either they start with the snare, the hi-hat, the bass drum, or whatever. But such considerations are swept aside the first time you come up against a machine on which all the instruments are of a 'peripheral' nature. You can't exactly start building a rhythm pattern with a whistle - long, short, or otherwise.

Admittedly, the size of the problem is dependent on whether you've got a concrete idea in your head of what you're trying to achieve. It's also eased considerably if you're using the 727 in conjunction with a conventionally-voiced drum machine. But make no mistake, 'jamming' with a Latin box is a much riskier business than powering-up a bass-and-snare machine and inputting the first thing that comes into your head.

"Operation: Programming Latin rhythm patterns isn't nearly as straightforward as performing the same job on a rock machine."

To conclude, I have to admit the TR727 is huge fun to use - even if Latin Percussion voices aren't 100% to your taste. Most of the sounds here are impeccably reproduced, and once you're over the 'where do I start?' programming dilemma, writing patterns is a real doddle. And that's true regardless of whether you're using the 727 to complement a traditional drum machine, or whether you're intending to use it solus.

I also have to admit that from an economic standpoint, the Stateside convention of letting the musician buy add-on voice cartridges is a good deal easier on the wallet. But it has its drawbacks. For one thing, it assumes that you want a conventional drum machine in the first place, and for another, it still precludes the simultaneous onboard programming of both internal and external voices. In a lot of cases, anyway.

It's to Roland's credit that their sloth in adopting ROM cartridges for additional voices hasn't been matched by a reluctance to offer storage of rhythm patterns on plug-in RAM. Because like its more conventional sister, the TR727 has a built-in slot that accepts MC64C RAM cartridges, which has to be good news for anybody fed up with dumping a whole gig's worth of rhythm patterns onto the far from dependable medium of cassette tape.

I doubt that the TR727 will sell in numbers that even approach the total achieved by the 707, but if it adds a bit of spice to what musicians can get out of today's rhythm technology, it'll justify Roland's decision to launch it in the first place.