Home keyboards have traditionally been the butt of jokes for the synth-playing fraternity, but these days the more expensive examples are no laughing matter - even if they are great fun to use...

Home keyboard design has taken on a new lease of life in recent years as manufacturers have redefined their concepts of what features and what level of technology a keyboard instrument should offer. Consequently, the variety and quality of sounds improved, while today's better off home keyboards have acquired such workstation accoutrements as on-board sequencers, effects processing, and built-in disk drives.

Perhaps most significantly, keyboards have come out of the stylistic ghetto to which marches, polkas, waltzes and the like once assigned them. These days you're just as likely to be assailed by r'n'b, soul, house, hip-hop and 'world' music styles thumping out of the on-board speakers. What's more, keyboards have started to provide Style memories which you can program yourself, so you can be as up-to-date as you want to be.

Perhaps inevitably, MIDI is assuming an ever more important role in the lives of keyboard owners, as it gradually breaks down the barriers between keyboards and the wider world of MIDI equipment. Of course, during the past 10 years the thrust of MIDI-based technology has been towards giving musicians creative responsibility for all the parts in their music - quite the opposite of the keyboard's auto-accompaniment ethos.

Yet the reinvigorated keyboard market and the popularity of auto-accompaniment software like Band-in-a-Box (which is now available for just about every computer in the known universe) suggest that there are plenty of people who don't want to program their own rhythms or their own basslines. Certainly, for songwriters more interested in the chord sequence and the melody than the drums and bass, keyboards conveniently provide a backing band for trying out ideas quickly in a variety of musical styles.

The auto-accompaniment concept can only become more attractive as accompaniment textures start responding in an "intelligent" way to playing dynamics - as is happening with Interactive Accompaniment on Yamaha's PSR-6700 flagship keyboard, Dynamic Articulation on Technics' SX-KN1000 flagship, and Human Touch Accompaniment on Farfisa's Imminent F1 flagship. Perhaps, then, it's time for the once-derided auto-accompaniment section to take centre stage.

Among the companies pushing the boundaries of keyboard design, Yamaha are one of the most active - most recently with the PSR-SQ16 (reviewed in MT December '92). Their latest keyboard, the PSR-600, may not have all the trailblazing features of the SQ16, but the inclusion of an onboard disk drive on a keyboard costing £699.99 must count as a first. In fact, its disk drive appears to be the only feature distinguishing the PSR-600 from the £489.99 PSR-500, so the bulk of this review can be read as a review of the 500 as well.

In one respect the PSR-600 actually betters the much more expensive PSR-SQ16: where the latter has a hopelessly cluttered front panel, the 600's layout is a model of order and clarity. Unlike modern synths, which tend to adopt a minimalist approach to the user interface, keyboards typically maximise the number of front-panel controls, adopting a control-per-parameter approach. Sometimes, as on the SQ16, this can get a little out of hand! The 600, however, strikes just the right balance of features and front-panel space.

The sound world of the PSR-600, like that of Yamaha's SY85 synth, is an AWM-only affair - the company, it seems, have knocked FM on the head. However, the 600 doesn't match the SY85's sound quality, using instead an earlier generation of AWM and, by the sound of it, less well-specified D/A conversion. This distinction, which holds for Yamaha's more expensive keyboards as well, contrasts with Roland's approach, which is to use the same sound-generating technology across a variety of instrument types.

The PSR-600's 100 Voices cover what has become fairly standard ground on keyboards and synths alike, ie. acoustic and electric pianos, organs and guitars, tuned percussion, strings, brass, woodwinds, pads, acoustic and electric basses, and, of course, drum and percussion sounds organised into keyboard 'drum kits'. It may sound like a recipe for General MIDI, but the 600, unlike the PSR-SQ16 with its General MIDI Voice configuration mode, doesn't have any pretences towards being a GM instrument.

The PSR-600's sounds begin well with a very playable acoustic piano, after which comes the unconventional but pleasingly warm and full Flange Piano. The keyboard section also includes a reasonably funky Clavi, a soft, 'pretty' electric piano and a harder-edged, much grittier electric piano which has a sharp bass end. There are four electronic organ Voices of a percussive and bright disposition, but sadly no grungy, groovy organ for those r'n'b rave-ups!

The bass end is well catered for by 12 bass sounds, including a couple of taut, punchy, clean electric basses, a full-bodied fretless, a funky 'mute' bass (with and without echo), a couple of nicely woody (if a touch muffled) acoustic basses, and three punchy, if not particularly phat and phunky, synthbasses. All in all the PSR-600 gets high marks for versatility, warmth and general effectiveness in the bass department. Similarly, its drum and percussion sounds score highly for their variety, punchiness, vitality and grittiness. Drums and bass alike positively leap out of the onboard speakers when you crank up the volume.

With the exception of the warm, rounded jazz guitar and the funky, percussive mute guitar, the PSR-600's guitar Voices are a disappointment. The various solo strings aren't very appealing, either, though the ensemble strings, together with the few other pad sounds provided, are more successful.

Other Voices which come across well include several muted trumpets, horn and flugelhorn, piccolo, bass clarinet, oboe, pan flute and harmonica. The various saxophone Voices are somewhat less successful, and the 600 lacks a really strong synth lead sound. So, all in all a mixed bag, but deserving of a general thumbs up.

The PSR-600 provides a choice of four keyboard modes: Normal, Split, Single Finger and Fingered. The first two modes assign respectively one and two Voices to the keyboard, while the latter two divide the keyboard into auto-accompaniment chord (left hand) and melody (right hand) playing areas.

Single Fingered mode lets you choose from four chord types without having to know anything about chord structure; Fingered mode, on the other hand, provides you with 15 chord types and requires you to play the actual chords. Now, 15 chord types do not add up to a comprehensive harmonic vocabulary; in fact, none of the chord types go beyond sevenths, which is a touch restricting for anyone who's into using minor ninths, dominant thirteenths and the like.

Other keyboard features are Dual (for layering two Voices) and Auto-Harmony (for adding harmony notes to right-hand playing). In Split mode, each side can have its own Dual on/off and Dual Voice settings.

Four Voice Memories let you store keyboard configurations and recall them onto the keyboard at any time. In all you can have 16 such Memories - four for each of the 600's four Page Memories. The latter store all keyboard settings, Song data and Multi Pad data. When you save a file to disk, you're actually saving the currently-selected Page Memory; up to 12 such files can be saved to a single 3.5" DSDD floppy disk. These files are the only file types that the PSR-600 will recognise - you can't, for instance, save or load song data in Standard MIDI Files format.

Along with the notes that you play on the keyboard, you can trigger single drum hits, rhythm patterns and melodic note sequences by tapping the Multi Pads located towards the right-hand end of the keyboard. Each Pad memory is effectively a short sequencer track into which you can program whatever you want; these 'tracks' play at the currently-selected tempo, so they automatically sync to any active auto-accompaniment or Song. Usefully, you can cut short a rhythm or melodic sequence triggered in this way by pressing the Record/End button.

In its selection of auto-accompaniment styles the PSR-600 typifies the present generation of keyboards. Dance and pop styles rub shoulders with boogie woogie and rhythm 'n' blues, funk and soul styles with rock and Caribbean, jazz and swing with 'world' music and new age. At the same time, traditional keyboard fare such as bossa novas, mambos, cha cha chas, marches, polkas and Viennese waltzes aren't altogether excluded.

The 600's Styles are for the most part well conceived, though not always appropriately labelled. Among my favourites are some of the soul ballad, r'n'b, rock 'n' roll and reggae Styles, not to mention a riotous boogie woogie. Styles such as soca, calypso, hi-life, township and cajun are similarly full of vitality, and are guaranteed to get you smiling and tapping your feet. Personally, I would have gladly sacrificed the polkas, waltzes and such-like for some more African music styles - soukous, makossa and Afrobeat would do for starters...

The PSR-600's onboard sequencer provides five Chord tracks and five Melody tracks. The former each allow you to select a Style and then record the desired accompaniment chord changes with your left hand; these tracks are mutually exclusive - if you select a second Chord track it will replace the currently-playing track at the start of the next bar.

Chord tracks can be made to loop, so you can run each track for as long as you want; individual Chord tracks can record up to approximately 150 chords. The Melody tracks, on the other hand, can be used together but can't be looped. Each Melody track is polyphonic, can be assigned its own Voice, and can record in the region of 700 notes.

The most conventional way to use this sequencer (in keyboard terms, that is) is to record different song section accompaniments (intro, verse, chorus etc.) into the Chord tracks, then use the Melody tracks to add a melody over each section. But the PSR-600 will also let you limit the Chord tracks to providing just the rhythm part (by deselecting the other parts of the Style) and record your own instrumental parts into the five Melody tracks. Used this way, the sequencer gives you six parallel tracks to play with.

Although one of the Chord tracks must always be active, you can drop out the rhythm part by deselecting it in the Orchestration section. Another way to drop out the rhythm track is to record a one-bar Chord loop which has all the accompaniment parts disabled; this way you can drop out the drums for any period of time (to the nearest bar) by selecting the relevant Chord track.

The PSR-600 includes a Conductor mode which lets you record not only your Chord track selections but also any Melody track on/off settings you make while the Song is playing. Effectively, then, Conductor mode allows you to 'piece together' your songs live.

What you can't do with the sequencer is route any of its tracks to external instruments via MIDI; as with the auto-accompaniments, the sequencer tracks play internally only. This seems rather unfortunate, as incorporating MIDI'd sounds into a sequence is a logical first step for any keyboard user wishing to expand their equipment horizon. In contrast, the PSR-SQ16 and Technics' KN range of keyboards integrate their auto-accompaniments and onboard sequences with MIDI very effectively.

Selecting Multi Voice mode turns the PSR-600 into a 16-part multitimbral instrument via MIDI, with dynamic allocation of its 28-voice polyphony across the parts and the keyboard.

However, selecting this mode automatically disables the 600's Styles and Songs. This means that you can't use, say, the onboard rhythms in conjunction with externally-sequenced PSR-600 instrumental parts. However, if you're prepared to forsake the 600's 16-part MIDI multitimbrality, you can sync the onboard auto-accompaniments or Song sequencer to an external MIDI sequencer or drum machine.

The 600's keyboard can be set to transmit on any one MIDI channel (or any two channels when the keyboard is split). Unfortunately there's no keyboard local on/off mode - an omission which can cause difficulties if you're using the PSR-600 in Multi Voice mode in conjunction with a MIDI sequencer. Really, an experienced manufacturer like Yamaha shouldn't be slipping up in this way. With keyboard users increasingly venturing into the world of MIDI sequencers, synths, samplers and drum machines, Yamaha aren't doing themselves any favours with the PSR-600's either/or MIDI implementation.

Effects processing on the PSR-600 is limited to a choice of room or hall reverbs, and there are no programmable parameters. This is fairly typical for keyboards, which in this respect do lag far behind many synths. However, you can at least program reverb depth for individual keyboard and Multi Voice parts, or control reverb depth live via MIDI using controller data.

So how does the PSR-600 rate? For a start, it's a very accessible instrument, thanks to its uncluttered, clearly organised front panel and the fact that it's not overburdened with features - being a mid-priced instrument has its advantages. At the same time the range of Voices and Styles provided by the 600 make it a satisfyingly versatile instrument. And while the sound quality of its Voices may not reflect the current state of the art, their characteristic mix of grittiness, warmth and brightness is very appealing, in a rough-edged sort of way!

Although you can, in a limited way, use the PSR-600's onboard sequencer in a conventional multitrack fashion, it's really geared towards recording your keyboard auto-accompaniment/melody performances. If you want to take advantage of the 600's 16-part MIDI multitimbral mode, you'll have to use an external MIDI sequencer instead - and forgo the onboard auto-accompaniment and sequencing capabilities of the instrument. The fact that its auto-accompaniment and sequencer parts can't play via MIDI makes the PSR-600 even less suitable for anyone wanting to combine a keyboard with other MIDI instruments. What are Yamaha playing at here?

Whether you're learning to play keyboards, learning about music, or looking for a ready-made 'backing band' for songwriting or performing purposes, a keyboard has a lot to recommend it - and the PSR-600, providing you're happy to use it as a stand-alone instrument, is one of the best in the 'middle-bracket' price range.

Then again, if you're happy using a MIDI data filer - Yamaha's MDF2, for instance - or computer-based generic SysEx librarian software, opting for the PSR-500 makes more sense, as it's significantly cheaper than the 600. Also, a data filer or generic librarian software can, by their very nature, be used to store data from any MIDI instrument.

For those who like the all-in-one solution, though, the PSR-600 is the better bet. However, if you're only going to use the 600 as a multitimbral MIDI instrument, Roland's similarly-priced JV30 synth would, to my mind, be a better buy.

Price: Yamaha PSR-600 keyboard £699.99 inc. VAT

More from: Yamaha-Kemble Music Ltd (Contact Details)

STOP PRESS: For a limited period only the PSR-600 is available at a special offer price of £549.99 inc. VAT