MIDI Tutorial: Understanding MIDI on the Akai MPC

Initially, the concept of MIDI can be confusing, but hopefully in this tutorial you will realise that MIDI is pretty simple and has many uses. In this article I'll also be looking at the hardware configuration side of the most common two MIDI set ups, that of using the MPC to control a sound module, and of syncing the MPC to a computer DAW.

What is an MPC Sequencer?

Many people know that the MPC is a sampler capable of recording audio from a variety of sources. But in reality sampling is perhaps the weakest individual aspect of the MPC, because only the MPC4000 has a fully-fledged sampling engine and OS (thanks to it containing all the sampling features of a Z-series sampler). However, at the heart of every MPC is a powerful, intuitive sequencer.

What is a sequencer? It's a device for recording data about musical events, rather than recording the actual audio itself. With a sequencer, you do not record the actual sounds from the performing instrument, you simply record note data 'instructions', which can consist of pitch, volume, length etc as well as the timing of that note in relation to other notes. Once you've recorded your sequence, you can then play back these instructions to the MIDI instrument and the instrument itself will play back the audio based on the instructions you send it.

In a typical MPC, sequencer events are either recorded on 'MIDI' tracks or 'DRUM' tracks. MIDI tracks are used to send out these MIDI instructions to external MIDI sound devices such as sound modules, other samplers, keyboard synths, and probably most commonly these days, a VST software instrument within a computer host .

DRUM tracks also store sequencer events, however these sequencer instructions are not used to trigger sounds from external sources, they are used to trigger sounds from your MPCs own DRUM programs. But the idea is the same, although the data looks very slightly different.

So, an example of sequencer information in plain English would be something like this:

"At the start of Bar 2, play a low C note for exactly one bar, at a velocity of 50"

This information is what your MPC will store in its sequencer, but in a more structured, numerical format. So for example, the above information could be represented in your MPC as follows:

002.01.00  N:36 (C1)          D:384  V: 50

Where

• 002.01.00 represents the current position in the sequence (start of bar 2)
• N:36 (C1) represents which MIDI note to play (MIDI note 36 which is C1, the low C)
• D:384 represents the duration of the note played (384 sequencer ticks, which in the 96 ppqn resolution of most MPCs represents a length of 1 bar)
• V: 50 represents the velocity value, i.e. how hard the sound is hit (which can be anything between 1 and 127)

If on the other hand you are simply triggering a pad event within a DRUM program, the sequencer information would look like

002.01.00  P:A02( 36) T:  0    D:384  V: 50

As you can see it's similar, except this time because we are just triggering what is effectively an 'internal' sound module, the MPC just refers to the specific pad (P:A02, which is assigned MIDI note 36, C1). Plus there's an additional, MPC specific parameter (T: 0) which is what can control the tuning of the pad, but that's not important to this tutorial).

Understanding MIDI

But as you can see, the above information is very generic and is certainly not audio! So, to make a sound from this information, you have to send this information to a piece of equipment that is capable of reading this data and knowing that this data is an instruction to play a 'C note'.

This data stored in your MPC sequences is referred to as MIDI data, which is a standardised form of information storage and transfer, developed to allow instruments and sequencers to talk to each other in a common language. MIDI stands for Musical Instrument Digital Interface. MIDI data is stored in MIDI sequences and the data is sent to other devices via MIDI cables plugged into each devices' MIDI ports.

It's very important to understand one thing - Midi does not record, store or carry audio data, it only deals with instructional data that tells an audio playback device which sounds to play.

The MPC can record MIDI data to its sequencer by either manually programming the notes in via STEP EDIT or GRID EDIT, or they can be recorded in real time using the pad or an external MIDI controller (see below). Once that data is saved into the sequencer you can hook up any MIDI instrument that is capable of emitting sound and get the MPC sequencer to 'command' it play audio based on the instructions saved in the MPC sequencer.

For your MPC to transmit and receive MIDI data to and from other devices, you will need to use special MIDI cables connected to the MIDI ports at the back of your MPC and to the MIDI ports of the devices sending or receiving the MIDI data. MIDI cables actually allow the sending of up to 16 different MIDI signals through that single cable. We say that the data is sent over different MIDI channels.

So let's look at the hardware hook up basics for the two most common MPC MIDI requirements.

Playing a VST Instrument Via MPC MIDI

Let's assume you already have a MIDI performance loaded into your MPC sequencer, and you want the MPC to playback the sounds from a VST instrument loaded up in computer software like Reason. To do this you need to connect your MPC MIDI OUT to your computer's MIDI input using a standard MIDI cable.

Now when you play back your MPC sequence the MIDI data is sent to your computer and routed to the Reason VST instrument which will then play the actual audio. Of course you'll first have to configure Reason on a software level to accept the incoming MIDI (i.e. configure your MIDI interface to work with Reason, set the MIDI channels to route to the correct VST instruments etc), but that's beyond the scope of this article. If you need to learn the exact specifics on how to configure your MPC and computer to use DAWs such as Reason, Ableton, Pro Tool or Logic as MPC sound modules, I've written several books on this subject.

Inputting MPC MIDI Data With MIDI Control Keyboard

While you can use your pads to input MIDI data into the sequencer, there is nothing stopping you using any other external MIDI capable device to do the same. An external MIDI controller can be used to record MIDI data directly to a MIDI track in your sequence, or it can even be used to trigger samples assigned to a DRUM program, as each pad in an MPC program is assigned its own MIDI note (we'll cover that in a different article!).

Why use a control keyboard instead of your pads? Well the pads are fantastic many purposes (e.g. finger drumming, rapid repeats, general input), they are not so great if you want to record, for example, a complex piano performance into your MPC sequencer. Keyboards also have an extended range beyond the typical 64 pad range found in most MPCs (remember you will often be triggering an external module, so are not limited to only 64 sounds, most sound modules have virtually infinite note ranges).

A MIDI control keyboard is simply a keyboard that can be used to transmit MIDI data, it has no actual sounds inside it. It has no MIDI input port, only MIDI output. Set-up is simple. All you do is connect one end of a MIDI cable to the MIDI out port of the control keyboard and the other end to the MIDI IN port of the MPC (I would connect to MPC MIDI port 1 by default).

Notice in the above diagram that there is no audio connection to the MIDI control keyboard, there's only a MIDI connection to the MPC. When you play a key on your keyboard, the note you play will have all the properties we discussed earlier (MIDI note, length, duration, velocity etc), and often many others such as expression data. All this information about the note you are playing is sent down the MIDI cable to your MPC's MIDI input.

If you have a sample program assigned to your current sequencer track, this incoming MIDI signal will trigger the sounds in that program. Alternatively if your MPC is connected to an external MIDI sound source (we'll see how to later), then this incoming MIDI data is actually passed along to the external sound module, which will in turn lead the sound module to playback audio. And throughout this entire process, you can also have your MPC simultaneously recording this incoming MIDI data to a sequencer track.

Combining The Two

So combining the two examples so far, we can play MIDI data into our MPC and in turn simultaneously trigger the sounds of a computer VST instrument using the set up below:

So you play a note on the control keyboard which sends the MIDI data about that note to your MPC sequence track. You configure that track to output MIDI over a specific MIDI channel which in turn is transmitted to your computer's MIDI interface and routed to your VSTi, where it plays this MIDI note as audio.

All this time, you can also have your MPC sequence recording these events to the MPC sequencer (i.e. REC AND PLAY START), so at a later date the entire performance can be replayed using the stored MIDI data.

Syncing Your MPC With A Computer DAW

When 'tracking' your MPC beats for final mixdown, it's common to to record both the audio and MIDI data into a computer DAW such as Pro Tools or Logic Pro. As part of this process, many producers will use MIDI to 'sync' their MPC and DAW together. What is MIDI sync? Well, it's yet another signal that gets sent over a MIDI cable, completely separately to the 16 channels of note event data. MIDI sync messages allow two or more MIDI devices to 'lock' together so they play back at the same tempo and also allow one device to control the other's playback (STOP, START, FORWARD, etc).

MIDI sync comes in a few 'flavours', and I cover this in more detail in this tutorial. When it comes to syncing, one device normally does all the 'controlling' and is referred to as the master. The device being controlled is the slave.

With the MIDI cable set up discussed so far, where the MIDI cable is going from the MPC MIDI OUT to the computer MIDI IN, we are already set (from a hardware perspective) to have the MPC as the MIDI sync 'master', because that MIDI cable will send the MIDI sync protocols to the computer.

However some DAWs require that they are the master. Also, transport protocols like MMC (which for example let the stop button on one device stop playback on the other) can work in both directions. So to satisfy these situations, we simply get another MIDI cable and connect it from the computer MIDI OUT port and into the MPC MIDI IN port.

This connection is called the 'midi handshake' and is the configuration I tend to have set up permanently as it covers most simple day-to-day MIDI requirements. Here both devices can always communicate via MIDI in both directions without having to re-route MIDI cables. And not only will this cover your syncing requirements, it also covers two-way traffic for all other MIDI data. For example, the MPC can send MIDI data to a computer VST instrument, but equally, the computer can send MIDI data back to the MPC which can then be used to trigger MPC sounds or be recorded into the MPC sequencer.

As with the previous examples, there will also be software configurations to consider as your MPC needs to be told which MIDI sync protocol to use and which MIDI port to send or receive the sync data from - this set up varies between each MPC model. Additionally your computer DAW will also need to be configured correctly and this will depend on the specific DAW you are using. Check out my many 'MPC-DAW' books to see if I have written one for your unique set up (my books cover the exact set up for all standalone hardware MPCs, and at the time of writing cover Pro Tools, Reason, Logic and Ableton Live). I intend to write books for all the most popular DAWs, so please let me know which DAW book you'd like to see next and I'll move the most popular request to the top of the list!

What's Next?

I hope this introduction to MPC MIDI has helped you understand some important MIDI concepts. Yes MIDI can get more complicated when you introduce additional MIDI devices with more complex requirements, and we'll look at some examples of that in a different article, but for many MPC beat makers, especially those working with a computer DAW, the configurations listed here will serve you well for the majority of day to day beat making duties.