Direct-to-Disk Studio System
Here's a computer-based sequencer with a difference - PROMIDI records direct-to-disk, lets you structure your music any way you please, and runs on low-cost PC compatible computers. Ian Gilby investigates...
Here's a computer-based sequencer with a difference - PROMIDI records direct-to-disk, lets you structure your music any way you please, and runs on low-cost PC compatible computers. Ian Gilby investigates...
Like motor cars, computer-based MIDI sequencers tend to look very similar - it's only when you get down to the fine detail that their important differences become apparent. Most sequencers are designed to work either like a solid state tape recorder, offering multiple parallel tracks, or like a drum machine, with repeating linear patterns of notes chained together to form a song. Both implementations have their advantages and disadvantages, depending upon the cleverness of the design, so it would be fair to assume that the 'ideal' MIDI sequencer should be a combination of the two with a few extra features thrown in for good measure.
The PROMIDI Studio System from System Design Associates (SDA) fits this description in many ways. It differs from most other sequencer packages on the market in that it records and plays back directly to and from your computer's disk; floppy or hard. PROMIDI uses the concept of files, rather than tracks, to record and process your MIDI data. Each file can record (and play back) data from all 16 MIDI channels simultaneously - some sequencers permit only one MIDI channel per track to be recorded. Since the number and length of files that you may record is limited purely by the storage capacity of the disk you are using, your music is no longer restricted to a set number or given length of tracks.
SDA reckon you can record over three million notes on a 20 Megabyte hard disk (that's a lot!) and around 60,000 notes on a standard 360K double-sided 5¼ floppy disk. The limiting factor with other sequencers is usually the size of the host computer's memory (RAM). This has to be large enough to allow the program to load into memory whilst leaving sufficient RAM space free for note storage and manipulation. Problem is, as programs become more sophisticated they grow larger and larger and take up even more memory space, thus reducing the note storage capacity further until, eventually, the program can only run on expanded memory computers.
This is not the case with PROMIDI. It requires a minimum of 360K of RAM to run and at least one 360K floppy disk drive. Since it records direct-to-disk, it requires no additional RAM for note storage. I used an Amstrad PC 1512 double-drive computer for the review, fitted with a Western Digital 32 Megabyte hard card (a hard disk drive on a circuit board that plugs neatly inside your PC), which effectively gave me unlimited note capacity. If you own a PC or intend buying one, I recommend you invest in a hard disk or hard card - it makes computing life far more convenient. To give you some idea of cost, I bought my 32 Meg hard card from Evesham Micros for £279 inc VAT; the equivalent capacity Macintosh or Atari compatible models will set you back £600-£800. (Now you know why I prefer to use a PC!!) Although PROMIDI works OK on a floppy disk system, it has really been designed with a hard disk system in mind.
PROMIDI comes on one 5¼" floppy disk, along with a ring-bound 94-page (photocopied) manual, MIDI cables, and a device called the MIDIcard. This is a 9" long circuit board which plugs into one of the expansion slots inside your PC. It houses Tape Sync In/Out and Metronome phono sockets, as well as a 9-way D-type socket into which you plug the extremely short (one foot long) 'Y' cable supplied by SDA. This is fitted with two DIN connectors (MIDI In, Out) at one end and a 9-way plug at the other.
The MIDIcard talks to the computer 15 times faster than MIDI and is not compatible with the industry standard PC MIDI interface, the MPU401 (unless fitted with a forthcoming special adaptor, called MIDIcard+, which costs an extra £65 or so). Once the MIDIcard is installed inside your computer, PROMIDI can be run either from the supplied floppy disk or it may be 'installed' on to your hard disk. Whenever you load the PROMIDI program, the operating system is downloaded to the MIDIcard. This makes it convenient to upgrade PROMIDI to a new version just by loading a new disk. As the program won't work without the MIDIcard, there's no need for copy-protection on the disk.
PROMIDI has been around in one form or another since 1985 and, like most PC-based sequencers, makes little use of graphic screen displays. The program is menu-driven and utilises the computer Function keys (F1-F10) to call up various sub-screens and to change parameter values. Although each screen lists the available functions and which keys select them, the keys perform different tasks on different screens. As a result, I found myself having to check the screen each time to find out what function a key performed - even after a prolonged period of use.
If you get stuck while using PROMIDI, there's no need to rummage around for the manual, you can either press the Escape key (to take you back up a screen or two to the Main Menu) or type 'H' from anywhere in the program and it will respond by displaying Help notes about whatever task you are trying to perform at that moment. The information provided on the Help screens is concise and genuinely helpful, and reading it is a very good way of coming to grips with PROMIDI quickly.
On boot up, the Main Menu shows six other screens which you can access by pressing the appropriate Function key: (F1) Directory; (F2) Play/Record; (F5) Mixing; (F6) MIDI Channel; (F9) File Maintenance; and (F10) Filter.
Pressing F2 takes you to the Play/Record screen, where you can begin realtime recording very quickly by typing T (to create a 'temporary' file called T.01) and pressing F10. Tapping the spacebar ends recording. If you don't like what you just played, you can press 'T' again and quickly record another take. PROMIDI gives this second 'T' file a different version number (T.02) to the first to avoid overwriting what you have just recorded. If you wish, you can record up to 99 different takes in this manner then choose the one(s) you want to keep, or select parts from each to form a new file. It's good practice to rename these 'T' files with something more descriptive to help identify them. Filenames may be any combination of letters and numbers up to eight characters long.
The alternative to this is to designate a record file on the Directory screen before you commence recording. As with temporary files, you can record up to 99 consecutive versions of any MIDI file - PROMIDI automatically assigns each one a unique version number. It's a very neat system, which prevents you accidentally erasing a file but doesn't stop you getting into a real mess if you forget which version is which!
PROMIDI actively encourages you to create and use directories and subdirectories ('folders' in GEM parlance) to help organise your various types of PROMIDI file. You could create a subdirectory for each song file, NEWSONG or SHUFFLE3 for instance, or for a certain MIDI instrument, then store all the pertinent files in those directories. You can Create, Record, Play back, Edit, Mix and Filter files in a subdirectory. You can also use the File Maintenance screen to Copy them into other directories on the same or other drives. As a safety precaution, you cannot delete directories or subdirectories from within PROMIDI (but you can move MIDI files from one directory to another).
Due to the way PROMIDI is structured, it splits things into Playback or Record files. In order to monitor what you are recording, you must designate the file you are working on to be both a Play and Record file. If you want to replay multiple files (think of them as 'tracks' for the present) whilst recording a new part, you need to create a special Listen file that contains all the files you want to hear. This is done on the Directory screen. However, this Listen file is only temporary and is overwritten each time it is created. To avoid this, you use PROMIDI's Mixing screen to combine all your Playback files into one, then specify this filename as your Playback file when creating further files. It sounds a rather long-winded process, and it is. But you get used to it in time, and come to appreciate the flexibility it offers.
I dislike SDA's use of the term 'mixing', however. It is better described as file 'merging', as you have no control over the playback level. You can mix (merge) up to six MIDI files in one go and there's no limit to how many times you can remix previously mixed files. Also, when you mix files down, the originals remain intact, so you can remix them if you change your mind or use them in other work.
• AUTO-CORRECT: PROMIDI provides a useful range of quantisation options for correcting timing imperfections that invariably occur when entering notes in real time from a keyboard. These come in the guise of a versatile Auto-Correct function, available as an option from within the Filter screen. Three different types of quantisation are offered:
MaxAuto - simultaneously shifts both Note-On and Note-Off commands (so that note durations remain the same) and MIDI Controller messages, such as Aftertouch, Pitch Bend, etc.
Simple - shifts Note-On and Note-Off messages in time (as per MaxAuto) but MIDI Controller messages are not moved with the notes. This may cause undesirable results, so Simple auto-correction is best applied only to files that contain no MIDI Controller information, such as drum tracks.
On Only - shifts Note-On messages only, which means note lengths will change.
PROMIDI's internal clock resolution is 192 pulses per quarter note (768 per 4/4 bar). You can auto-correct your music to any beat division you like below a quarter note, including triplets. To add further control over the 'feel' of a piece, when MaxAuto is selected you can shift notes either ahead of or behind the beat by as much as an eighth note (96 pulses), and add a 'swing factor' to your music (0-100% in 12.5% increments) to simulate a triplet feel. Furthermore, you can choose whether you want the time-shift to be done before or after the MaxAuto correction, which can make a terrific difference to the overall feel of the music.
• VELOCITY CONTROL: Time spent attending to the small details when recording your sequences can often pay dividends during the mixing stages. These days, many sequencers offer some form of note velocity adjustment. Since velocity is nearly always employed to control the amplitude of notes on synths and samplers, it provides the means with which to carefully balance the playback volume of instruments, performing functions akin to a compressor or limiter.
With PROMIDI's Velocity Control filter, you can globally adjust or limit the range of note velocities in a MIDI file. Alternatively, by specifying start and end beats, you can choose to filter the velocity of a solitary beat or the entire file. You can also control Dynamic Range and Gain.
In PROMIDI terms, the Dynamic Range is the allowable range for velocity information in a MIDI file. Usually, MIDI recognises note velocity values between 1 and 127; this option forces all the velocities to fall within a user-definable range. This is different to the 'scaling' options found on other MIDI sequencing programs but useful nevertheless for ensuring level consistency when changing from one synth patch to another. If you want to raise the volume of all notes in a chorus, say, but keep them within the allotted Dynamic Range, you can specify an amount to be added to or subtracted from each note velocity using the Gain option.
• CHANNEL MANAGEMENT: This highly flexible filter option allows you to Extract or Copy MIDI messages for any or all MIDI channels from a MIDI file; Extract or Copy only a note with a particular pitch; Extract or Copy all notes within a range of pitches; and automatically change the MIDI channel number of the Extracted or Copied MIDI messages (clever!). By toggling on/off the kinds of MIDI channel messages that you want, you can Copy or Extract Notes, Program Changes, Sustain Pedal, Pitch Bend and Aftertouch (Pressure) separately or in any combination.
The facility to Extract or Copy a single note is important when processing MIDI files containing drum parts, where each 'drum' (snare, cymbal, etc) is assigned a particular pitch (MIDI note number). Extract removes messages from the Source file, Copy leaves the Source file unchanged.
As with all other filter functions, PROMIDI requires you to specify a Target file where it can store the filtered data. If you mess things up when filtering, you then have the option to Mix the Target file back into the Source file and start again - a very welcome feature. Most sequencers don't allow you to undo your mistakes quite so easily.
• TRANSPOSITION: As you'd expect, note data in a PROMIDI file can be shifted up or down in pitch by any musical interval (3rd, 5th, etc). In addition, you can transpose according to one of four scale options (Major; Natural, Melodic and Harmonic Minor) - not quite as varied as the Pitch Transforms on Sequencer Plus but interesting nevertheless. Scalewise transposition means you can transpose your music while keeping it in the same key signature. Transposing a melody line twice in this way, but altering the transposition amount each time, is a very quick way of producing perfect three-part harmony. PROMIDI will create two new Target files containing the second and third parts, with the Source file holding the original melody. You can either replay all three or merge them back into one file using the Mix function. PROMIDI doesn't restrict transposition to whole files either; you may pitch shift any number of consecutive beats, wherever they occur. Most sequencers permit only whole tracks or whole numbers of bars to be transposed.
• SLIDE: Allows you to time-shift a MIDI file forwards or backwards in increments as fine as one PROMIDI clock (1/192nd of a quarter note beat). It can be used to create double-tracking or echo type effects (by replaying several duplicate files slightly out of time with each other) and to compensate for slow note triggering (of a sampler, say) or for unwanted MIDI delays created by 'daisy-chaining' several MIDI devices.
The MIDI Channel screen is where you configure PROMIDI for the requirements of your specific MIDI set-up by toggling the Record and Thru function on or off for each MIDI channel in use. PROMIDI defaults to all Record channels on and all Thru channels off, which is the set-up required to allow one MIDI instrument to talk to the host computer and the computer to the instrument. But when you use more than one MIDI device, you will need to toggle Thru channels on. For example, if you have a keyboard and a separate sound module or some similar combination, those devices can't send and receive messages 'through' PROMIDI unless the Thru channels are turned on. You can use PROMIDI's 'Save Keystrokes' feature to store your channel configuration on disk and have it automatically load each time you power up.
PROMIDI lets you record one MIDI file whilst playing back another. In fact, this is how you multitrack. You can do this repeatedly and your files always stay in sync.
To overdub you must have both Playback and Record files. The Playback file can be a 'Listen' file or named file. The Listen file consists of any file or combination of files in the current directory. It makes overdubbing easier if you use the metronome as a timing guide and record a fixed count-in of a few beats. You can remove the count-in later with the Trim option.
To fast-forward or rewind through a Playback file, you hold down the left or right cursor keys. The Beat count in the Status box changes to inform you of precisely where you are in the file. As well as displaying the current Beat number, it shows the Measure number, Beat In Measure number, Time Signature and current Tempo. Trouble is, it does not give you this information on the Step Editor screen, where it is of far more use. You are told only the Beat number.
Most of the functions you need to use regularly are accessed from the Play/Record screen. These are grouped into four different Levels of operation, and you cycle through them by pressing the plus (+) key and selecting the required operation with the appropriate odd-numbered Function key (F1, F3 etc) indicated on-screen.
No real thought appears to have gone into the order in which functions are grouped, unfortunately, and you find yourself having to press the + key four times followed by F1 to activate an important function like Cut/Blank. Yet the Queued function, which determines whether PROMIDI is controlled from an external or internal clock source and is likely to be set at the start of a session and left, is accessible from the top-most level with a single keypress! It smacks as if functions have been added willy-nilly over the years as the program has been developed. Of course, this doesn't stop you using the program, it just makes it less intuitive and slower to come to terms with.
In all there are 20 different Play/Record functions, grouped as follows:
|Level 1||Level 2||Level 3||Level 4|
|F3||Queued||Punch In/Out||Punch Leader||Paste|
|F5||Time Sig||Master On/Off||Punch Trailer||Metronome Lo/Hi|
|F7||Metronome||Omni On/Off||Display Marks||Chain|
|F9||Punch Data||Loop On/Off||Set Mark||(Unused)|
Not everybody can play a keyboard in real-time without fluffing the odd note or two, which is why all good sequencers provide tools with which to edit what you have recorded, usually in varying degrees of detail. PROMIDI is no exception: its Step Editor allows you to edit individual existing notes in a MIDI file; to Add or Delete new notes; to change their attributes; and to Step Record single notes and chords. Both MIDI data and note data can be edited.
The Step Editor loads up to 1000 beats at a time into an Edit buffer in the computer's memory, and using the Function keys you can alter the Position, Duration, Velocity, Pitch and MIDI Channel of any note shown in the Note Window. These note attributes are listed below the Note Window for whatever note is nearest the cursor.
A cross ('x') in the Step Edit window indicates the location of non-note MIDI messages such as Program Changes, Pitch Bend, Aftertouch, Time Signature changes, etc. Notes are shown as horizontal lines.
Cursor position is indicated visually by the marker along the bottom of the Window and numerically in the readout below it. I couldn't get used to the fact that only one note is visible in the Window when you play a chord; multiple Note-Ons are shown graphically on a keyboard along the bottom of the screen, and to edit them you step through each note of the chord in succession. Very strange! Displaying notes on a graphic keyboard as they play is a very good idea, though, and only serves to highlight the dichotomous nature of PROMIDI's Step Editor. In some ways it is antiquated, in others it is advanced. Being restricted to viewing only one, two, or four beats at a time, according to your chosen 'magnification level', makes it difficult to gain an overall picture of where notes lie in relation to others and leaves you 'groping around in the dark' a bit too much for my liking.
Note Position and Duration are referred to in terms of PROMIDI's resolution of 192 clocks per beat. A Position value of 56, for example, tells you the indicated note begins 56 clocks into the current beat. A Duration value of 384 tells you the indicated note is precisely two quarter beats long (provided you can remember that 192 docks equals one beat). Velocity and Pitch are shown as MIDI values, 0-127, though Pitch is also indicated in conventional scale terms.
Notes may be added at the cursor position with the plus (+) key, but you have to move the cursor to the exact Note-On position (start) before you can delete the note with the minus (-) key. Each individual note also sounds as you skip through the file with the left/right cursor keys, or you can sound the current note or chord by tapping the spacebar.
Although you may enter notes in the Step Editor directly from the computer, the better way is to utilise PROMIDI's ingenious Step Record mode and input notes on at a time from an external MIDI keyboard. PROMIDI lets you assign a different Step Note value to individual keys on your keyboard (as many as you like). For instance, the low C note may be defined as a quarter note, D might be an 8th, and E might be a 16th, etc.
To input a note or chord of a desired duration, you simply hold down the corresponding Step Note and press the required keys to define the pitches. When you release the key, PROMIDI automatically advances the file by the equivalent step value. To tie notes, you hold down the note you want to sound and press the necessary Step Note one or more times, depending on how long you want the note to be. Rests are equally easy to specify - you just press and release the Step Note corresponding to the required length of rest. Pitched notes are registered only when a Step Note is held down and a second key is pressed. If you make a mistake, you can correct it with the Step Editor in the aforementioned manner.
This system makes step-time recording extremely quick and easy to perform - and, dare I say, viable. It would be better still if PROMIDI's graphic keyboard could show the Step Note values you have assigned to particular keys. As it stands, you either have to rely on your own memory, jot the values down on a scrap of paper, or write them above the respective keys on your instrument.
My only real complaint is that PROMIDI forgets all but the last six Step Note values you define if you exit the Step Editor screen. If you are step recording a long, complicated piece of music where you have defined a dozen or more different Step Note values, you very quickly grow sick of having to redefine most of them whenever you exit Step Edit to play back your file (something you tend to want to do quite regularly).
If there is one thing I have learned in the two months I've been using this system, it's that the 'p' in 'PROMIDI' stands for power! If you want power, you usually have to make a few sacrifices in order to obtain it; and in PROMIDI's case, what you will have to sacrifice is your time. Sophisticated computer programs all take time to learn. That doesn't automatically mean that they are difficult to use, though. You can be up and running with PROMIDI in a matter of minutes and using it to produce useful work. All the interesting stuff comes with practice.
Having started out disliking PROMIDI, primarily due to its slightly haphazard user interface, I quickly grew to marvel at its sheer flexibility. The limitations I thought it initially had stemmed from my own inability to discard the idea of sequences being 'track' based, not from any inherent functional limitation of the program. Apart from the restricted note-viewing capability of the Step Editor, I haven't found any as yet!
Unlike most other sequencers, PROMIDI doesn't restrict you to a set number of tracks or notes; its direct-to-disk recording means you are limited by disk capacity not by the available RAM in your computer, which makes it possible to create inordinately long songs without any repeats. Nor does PROMIDI force you to Extract, Copy, Transpose, Auto-Correct and Filter multiples of whole bars only - you can manipulate anything from a single beat to a whole file if you so wish. The Universal System Exclusive Librarian incorporated within PROMIDI really is universal; it will even record voice dumps from those MIDI instruments that require some form of 'handshaking' before coughing up their internal patches. In a busy studio environment, PROMIDI would be ideal for storing the patch data from all MIDI synths, drum machines, and effects used on a session, and would quickly pay for itself in terms of the setting-up time saved.
At £399 inc VAT, PROMIDI ranks as one of the more expensive sequencing programs around. That price does include its own MIDI interface with sync-to-tape facility and a powerful SysEx Librarian, mind you, so there's no need to buy any more costly RAM packs for your machines.
The downside? It has to be the fact that PROMIDI's MIDI interface cannot be used with other, MPU401-compatible, software at present. Only Bacchus' Voice Manager series of editors will run on it, although I was told SDA were releasing the MIDIcard+ adaptor (£65) any day now, which makes it fully compatible with any MPU401-based program.
To summarise, PROMIDI is an extremely professional sequencing system that will do almost anything you want it to. Add a hard disk and it has the power to outperform any other sequencer on the market.
£399 inc VAT.
MIDI Music, (Contact Details).
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Review by Ian Gilby
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