MIDI Live

Paul Overaa offers beginners some basic advice on using MIDI live.

It's happened to the best of us. You set up your MIDI gear on stage, say the right spells and incantations, press the start button on your sequencer or computer... and then either nothing happens at all, or the wrong thing happens. MIDI problems do crop up from time to time, but 99% of the time it's something very simple — wrong connections, faulty leads, or perhaps a MIDI unit or sequencer that has been set up wrongly. Although it is quite rare for MIDI equipment itself to 'go down', hardware failures, especially with computer‑based sequencers, are part of that 1% of non‑simple problems that can arise. I've been doing live gigs using all manner of MIDI sequencing gear for around 10 years now, and with over 1000 such events under my belt, I feel fairly comfortable using MIDI live. There have been many minor hassles through the years, but I've had only one serious problem — a drive failure on the boot‑up drive of my computer.

Common Problems

The odd snag no longer worries me, but if you're a newcomer to the MIDI revolution the situation is likely to be different — any problem will be worrying if you're getting ready for a gig. Before you panic, however, it's worth getting into the habit of making a few simple checks. Even though most pieces of equipment have their own quirks, fault‑finding will usually follow the same basic scheme. I'll assume, for my examples, that a computer sequencer‑driven setup is being used, but the same ideas apply to all MIDI systems.

NOTHING HAPPENS WHEN THE SEQUENCER STARTS

• First, check that your lead connections are correct: the sequencer's MIDI Out to the first unit's MIDI In, then MIDI Thrus to the MIDI Ins of successive units, if you're daisy‑chaining MIDI connections; the sequencer's MIDI Out to your Thru box MIDI In, and then a MIDI Out to the MIDI In of each unit, if you're using a star network arrangement.
• If this doesn't highlight any obvious fault, the next stage is to check that the computer or sequencer is actually generating MIDI data — and that it's coming down that first cable. Some sort of visual indication is needed here, and Studiomaster's MA36 MIDI Analyser is ideal for this type of check. Unplug the lead feeding the first MIDI unit or Thru box, plug in the MA36, and you'll get an immediate LED visual indication of what MIDI data, if any, is coming down the line. If you haven't got an MA36, hopefully you'll have at least one synth or expander module that has an LED which blinks as data is received. Although not ideal for fault‑finding, these do at least give you some visual indication that MIDI data is being generated (see the 'MIDI Gadgets' box for details of one or two other devices that can make life on the road easier).
• If these checks reveal that no MIDI messages are being transmitted, replace that first cable with another and try the system again. If necessary, continue to check the other units and lead connections in the same way. Once you're happy with the physical connections, check the channel/mode assignments of the individual MIDI units.
• Don't forget any battery‑powered MIDI connectors/pedals, etc. A lot of people make a connection from the sequencer to a Thru box to provide a star network arrangement. I've seen two cases where people have placed battery‑powered Thru boxes inside their rack units — it's a great idea until the battery packs up!

A SYNTPLAYS BUT SOUNDS WRONG

• Usually this is a channel/mode problem resulting either from a unit being set to 'Omni‑On', or set to receive the wrong MIDI channel. The solution is to re‑check the channel and mode settings for the unit. Don't forget that wrong channel assignments can result in a unit responding to program change commands which were not originally meant for it — so suddenly hearing synths switch to different voices to the ones you expect is another useful sign to watch for.
• Quite a few variations on this theme are worth mentioning. Your sequencer will usually have drum channel facilities which protect drum parts during transposition. If you are using arrangements with transposed sequences and have forgotten to set (or have incorrectly set) the drum channel value, any transposed sequences will include transposed drum track data. The result, of course, is that your drum part will be either non‑existent or sound totally different from that expected.
• Another common slip is failing to set the MIDI clock option on a drum machine. If a drum machine is using its internal clock, and you inadvertently pump additional MIDI clock data into it, strange (and often unmusical) things will happen. If you hear this sort of effect, go straight to the sequencer drum channel assignmentoptions and the drummer MIDI clock options, and check that they have been properly set.

Less Obvious Faults

Methodically checking connections, leads and channel/mode assignments will, for the average MIDI system, take less than five minutes. In almost all cases, you'll find where the trouble lies and be able to correct the fault.

Occasionally, a less obvious problem may occur. If, for instance, you use your MIDI gear at home or in the studio, you're likely to change any number of front‑panel parameters. The danger is that the gear gets packed away and taken to a gig with these changes still in place. Depending on what you've been doing, you might have reassigned and memorised different controller settings, or changed the program change mapping characteristics.

This type of problem is, for obvious reasons, far more common if equipment is used by several different people — and the more programmable a MIDI unit is, the greater the number of pitfalls. For example, many synths can be configured so that they have several note data channels, and perhaps even a separate control message channel. Some devices can be set to ignore certain types of data, and can even be made to modify or filter the data they receive. All this can add to the confusion if you're not familiar with the equipment being used.

The golden rule is this: if you have to use borrowed or hired MIDI gear, make sure you understand how to interrogate the front‑panel parameters of the equipment and get a copy of the manual at the time you collect the equipment. It's better to be safe than sorry! Remember also that if you borrow synths/expanders which have user‑definable program change tables, you may need to alter various table entries to suit your own voice/program‑change command requirements.

Another hidden nasty in this area is the fact that many MIDI units, when switched on, assume an initial state that is a copy of their state when last switched off. It is conceivable that a MIDI device being used with a MIDI volume pedal and set to zero volume just prior to switch‑off could fail to respond when switched on at a later date without a controller pedal. With more and more effects units offering memorised settings and remote assignable controller facilities, it's possible that these problems might become more common, so bear them in mind.

Last Words

Do not court disaster unnecessarily. When out on a gig always make sure you take two or three copies of your data disks (and your sequencer program, if you're using a computer‑based system), have a few spare MIDI leads, and some visual means of conducting your fault‑finding tests. It seems almost too silly to mention, but a good torch is another handy item to carry around — most flightcases are black inside, and once the lights are down it's almost impossible to check back‑panel connections or unit wiring within the flightcase itself without having a bit of extra light around.