Using MIDI in worship: Ins & Outs - Part I by Lavon Oke

You may have heard some folks say that worship used to be and should remain simple. As we enter the 21st century, it is hard to imagine our lives without technology. It’s no surprise that all this has even come to change the ways and styles that earthly beings worship the infinite God. A survey of the holy scriptures would suggest many things about worship, but they don’t mention overheads, projectors of all kinds, sound systems, and electronics. This article introduces practically another element of technology: MIDI. This is an acronym for Musical Instrument Digital Interface.

Although this technology can do amazing things, one must keep it in perspective. As we prepare to use such tools in worship, it should be a top priority that anyone who would desire to lead others into the presence and worship of God, would do so with the utmost preparation and care. We have all seen our share of technology foul-ups. It may take a little time, but not using the "stuff" in worship until it is fully understood, is worth the wait.

Some Basic Definitions

The "Musical Instrument" part refers to electronic keyboards, drum machines, effect processors, and more. MIDI was designed for keyboards and tone generators, but as the control elements became more refined, it was added to a host of other electronic equipment. "Digital" simply refers to the fact that MIDI uses a stream of messages that are composed of only 1’s and 0’s. Simply put - computer talk! The "Interface" is the part that allows different instruments to communicate. Each "MIDI" instrument has an In, Out, and Thru. These are the ports through which messages are sent and received.

For most of us, the initial encounter with MIDI leaves the question, "but what does it do?" I would give the simple answer, but doubt that one exists to fit every person. Basically, focus on the "interface" part. The primary purpose and function of MIDI is communication. It will allow two instruments (which, keep in mind, are just computers in a fancy box with some piano keys out front!) to talk to each other.

When You

Press a Key

Each time an "event" happens on a keyboard (a note is struck), a microsecond evaluation is done by the computer. This includes how hard the key was struck (velocity) and what pitch it is (the note number). All this boils down to a "note on" message. When the key is released, it becomes a "note off" message. As you sit and watch a good keyboard player perform a wonderful arrangement of your favorite hymn, it’s amazing to think that each individual key stroke is evaluated by the on-board computer and compiled into a MIDI message stream at the same time. That is a fair chunk of processing!

Let me set up a physical scenario. Imagine you are in a church with a modern organ. (Even though you might not recognize this fact, most are becoming "MIDI capable"). You have a 5-pin MIDI cable and a second MIDI keyboard. The keyboard is set up on the stage at least three feet from the organ. They are totally separate from each other except for the lone MIDI cable that runs from the keyboard MIDI Out, to the organ MIDI In. What MIDI allows you to do is stand at the keyboard, strike a key, and hear the organ playing! It’s like a kind of remote control.

MIDI Data Is Not "Sound" Signal.

Keep in mind, all that is sent on the MIDI cable is data. If the keyboard has a different sound chosen (let’s say a trumpet sound), the organ will not "sound" like the keyboard would have - it only plays the performance or the "event" that happened on the keyboard. I have heard of folks trying to plug MIDI into the sound system. Nope, that won’t work either; it’s only computer data. This data is set up in a stream with codes for the next computer along the line to recognize. Each MIDI event message will contain information about the channel (there are 16 channels), the note number (the pitch), the attack and release velocities, and note duration. Each MIDI instrument can be set to "listen to" all the channels (called "omni mode on") or to one specific channel ("omni mode off".)

Linking Multiple Functions

Let’s get back to what it can do. It can connect one or even several other keyboard instruments to a "master" keyboard. This might come in handy when you would want to layer multiple sounds together. Perhaps a harp sound from one keyboard, and a soft string pad from another. The performance could be played by as many keyboards as were linked together with MIDI cables. This opens up a whole new world of sounds as different timbres can be blended with just one keyboard stroke.

The other area of control that MIDI offers is with timing or synchronization. Many of the events that happen in the MIDI world need to be happening at very specific times. If you have a drum machine or percussion module, you might want other events to happen in time with it. MIDI can do this. It contains a time code or "clock" that can be used to synchronize several things together. With the correct equipment, it can even run a light show! Many of the newer light controllers (for stage lighting) are MIDI-capable and will allow the light changes to be run through MIDI control. Getting all these components to work together is the deeper side of MIDI, but it can also become the "wow, how did you do that!!??" side as well.

MIDI Sound Generation

Let’s divide up these two sides of the MIDI world and look a little deeper. We will start with the MIDI instruments that generate sound. I doubt that any reader has come this far without ever seeing a keyboard. What you might not realize is just how many different types are available. You can buy one for as little as a couple hundred dollars, or as much as a couple hundred thousand. As we know, technology continues to advance and these instruments get more and more complicated. More features are added with new models and before you know it, one of them might actually make your coffee as well as sound great! The important thing to remember is that you get what you pay for. I can’t tell you how many have asked me where they could buy a keyboard that has lots of great sounds (that sound just like the real instruments), a big sequencer with lots of tracks, extra control features to be the master of a large system, lots of on-board effects, and a full 88-note piano-feel keyboard - all for $500.00!? Think of some of those nice cars with all of the great power features and leather and well, you know they don’t come cheaply. The same would be true for keyboards. The thing that I must state most clearly is this - you are going to buy a keyboard because of some eventual sonic experience! You won’t be looking for something to calculate your taxes. The best advice I ever heard on this is, "If you don’t like the sounds when you are at the music store (or wherever you audition it), you won’t like the sounds after you get home!" Be fussy with this - the rest of the features will come along in the package.

Perhaps the biggest advantage in sound generation that MIDI has brought to the world of music is the separate tone generator. The music industry has adopted a few "let’s all do this" standards. The 19" rack space is one of those. For years, famous keyboard players were looking for all the sounds they needed for a concert and ending up with six to ten keyboards on stage. These were in stacks all around them and they needed to be pressing buttons and crossing arm over arm just to get to all the different sounds. Enter MIDI! With the ability to play one tone generator from the keys of another, the question was asked "Why do I need to take all these extra keys with me if I can play all the keyboards while just sitting at one?" All that had to be done was to connect the MIDI cables and all ten keyboards would sound as a note played from just one. This got some engineers thinking. It occurred to them that they still needed the brains from those keyboards, but not the keys. Enter the rack module.

The keyboard manufacturers have taken the sound "engine" designs from their keyboards and put them in 19" rack modules. Imagine the relief of the road crew! Now, instead of setting up ten keyboards, they have all their brains or engines in a nice compact, rolling rack. And imagine the keyboard player - not having to stretch to reach all the different keyboards. They just step up to one master controller on stage. The only catch to this wonderful change is the growing demand on MIDI. All those tone generators will need MIDI messages to operate. Not to mention that each tone generator will need a separate line into the audio system so that it can be heard.

The practical implications for churches and worship are exciting. Most of what we do in these settings seems to emulate the "live performance" type of keyboard work. To take this technology into the worship service, one will need to ask, "What do we have and what do we need to add?" For more traditional worship styles, I have seen very effective use of the organ with a MIDI cable run to a second and third tone generator. This allows various orchestral sounds without losing the established organ sound (again, don’t forget that each tone generator will need an audio line into the sound system). Having a keyboard player or two, in addition to the acoustic piano, can create an ensemble with the musical range to cover just about anything most worship situations may require.

Control Aspects of MIDI

Let’s turn to the control side of MIDI. Data messages can be recorded in a sequencer. This is basically a multi-track recorder that uses computer storage - like tape recording is to sound. The huge difference is that each event can be edited. There are several types of these recorders. Some actually come on a keyboard and can be simple or complicated.

Others come in the form of computer software and are amazingly powerful. The best thing about it is flexibility. Let’s assume, for example, you record a nice piano track and want a solo instrument playing along with it. The piano data is on track one and the solo instrument is recorded on track two. Now, as you play back the recorded sequence, you can actually change the sounds you are hearing. Again, the data or keystrokes were actually recorded - not the sound. If you make a mistake, you can go back and edit that note and not have to rerecord the entire performance.

If you also have a drum machine, you could have a nice pattern programmed in to play along with your sequencer. Connect a MIDI cable to the drum machine, make it a slave to the time code from the sequencer, and it will follow along in perfect synchronization with your recorded sequence. For those light controllers that have MIDI capability, you can "record" the moves and changes on the MIDI sequencer and synchronize all the lights with the music as well.

Hopefully this provides a basic understanding. It would be hard to understand MIDI without some hands-on experience. Any large music retail outlet should have the equipment and the staff to explain more. For more technical information, try Keyboard or Electronic Musician magazines. And be sure to watch for Part II of this series.

Lavon Oke is Orchestra Director and electronic music consultant at Penn High School in Mishawaka, Indiana. He has also served as sound person and music leader in his church. He welcomes e-mail questions at: