Technology: MIDI Show Control
Technology: MIDI Show Control
James Cooke discovers how a system based on musical instrument digital interfaces can help bring various AV elements under control
What is MIDI?
Let’s start by defining MIDI (Musical Instrument Digital Interface). This is a protocol enabled by a digital interface and a series of connectors that facilitates communication between various electronic musical instruments, pro audio devices and computers. Pretty handy when you’re playing and recording music. Up to 16 channels can be routed through a single MIDI link and each of those channels can be sent to a different instrument, computer or device.
MIDI is also able to deliver event messages. These can be instructions for music, such as a notation, the pitch or velocity of a piece. Advantages of MIDI include its small file format, which is able to both store and exchange data, its ability to manipulate a wide range of electronic instruments, like synthesisers and keyboards, and its compatibility with different manufacturers. For example, before MIDI came into being in the early 1980s, different branded electronic instruments were typically unable to communicate. A Roland keyboard could not be connected to a Yamaha synthesiser module, for instance.
What’s more, using MIDI, a single controller can be used to play several electronic instruments at once, providing a degree of flexibility, and portability if needed, when it comes to setting up at the start of a service or event. This is because a single MIDI keyboard controller (or even software) can replace not only several full-size keyboard instruments, but outboard mixing and effects units as well.
What is show control?
Show control almost defines itself. It is the control of the elements of a ‘show’. This can include the music and audio aspects, as well as lighting, video, and rigging. Even pyrotechnics! In this context, we’re referring to technologies that largely automate these various show elements.
Show control systems tend to be built from multiple multimedia controllers or entertainment control systems, which together form one automated system. These systems are used for everything from concerts to live television productions, as well as at theme parks, public events and everything in between. They would certainly not be out of place in a house of worship with professional audio, video and lighting systems in place.
It should be reiterated that show control systems and entertainment control systems are not the same thing. An entertainment control system will manage one aspect, such as the lighting or sound. The show control system combines the various entertainment controls to form an all-encompassing solution.
MIDI Show Control
So, now we come to the crux of this article. What is MIDI Show Control? Often abbreviated to MSC, it is an extension of the MIDI standard – an open standard that follows real-time computing protocols to allow any and all entertainment equipment, including control devices, to communicate with each other. In other words, you can form an entire show control system using the format (that’s why it’s called MIDI Show Control and not MIDI Entertainment Control).
MSC was validated by the MIDI Manufacturers Association in 1991 and enables computers to perform show control functions automatically in live applications, such as a concert, worship service or event. As with the original MIDI protocol, MSC is used for transporting digital information and data, not the show media itself. As a historical aside, the first production to fully implement MSC was Walt Disney World’s Magic Kingdom Parade in September 1991, highlighting the complex show control that the protocol is capable of managing.
MSC data is transmitted just as musical messages in MIDI are sent to a synthesiser. While compatible with MIDI hardware, modern MSC devices typically rely upon an Ethernet connection, potentially ruling out older systems. The benefit of using Ethernet, of course, is flexibility afforded by the network’s higher bandwidth. The data sent via MSC can include all manner of performance parameters, such as lighting desk submaster and playback settings.
All MSC-compatible devices and instruments are able to communicate with each other and computers programmed to understand the messages as they all follow the same, standard MSC specification, using the MSC Command Set. This means each product transmits an identical message for the same MSC event, such as hitting a particular cue. As all MSC-compatible musical instruments feature a built-in MIDI interface, they are able to follow any number of MIDI-over-Ethernet protocols.
MSC messages are assigned to the cues that a device is able to manage within the show controller’s cue list. These are transmitted from the controller’s MIDI output automatically during the show, as commanded by either the user or the controller’s internally timed sequences.
Other show control options
There are, of course, other entertainment control alternatives available with which you can build a show control system. You will likely be familiar with, or at least have heard of, some of them. For example, you may have seen the letters DMX appear together in this magazine previously. USITT’s (the United States Institute for Theatre Technology) DMX512-A is often regarded as the current industry standard for lighting control systems. It works as a control method communicating between digital lighting consoles and entertainment lighting fixtures, dimmers and effects machines such as fog generators and strobes.
While USITT developed DMX512 in the 1980s, ESTA (the Entertainment Services and Technology Association) took over the standard in 1998. After ESTA revised it, ANSI (the American National Standards Institute – which established ANSI lumens as a measurement for light output of projectors) accepted DMX512 in 2004. Today, PLASA (the Professional Lighting and Sound Association) manages the standard, following its merging with ESTA in 2011.
Although several manufacturers, most of which produce lighting control consoles, pitched for DMX to become a show control standard for all AV elements, network limitations and lack of speed meant that the idea was never widely considered.
Other contenders on the audio end of the spectrum include Audinate’s Dante and CobraNet. The latter is the older of the two, having been around since the mid-1990s. It is considered the first commercially successful digital audio network solution. Using a mix of hardware and software to manage, CobraNet still enjoys a large installation base to this day and is licensed to several pro audio manufacturers.
Dante is another term that you may well be familiar with from browsing these pages. When it comes to audio networking, it is largely considered to be the heavyweight champion. Taking its name from the abbreviation of the phrase Digital Audio Network Through Ethernet, it is a propriety solution for distributing uncompressed, multichannel, low-latency digital audio via an Ethernet network.
Whatever systems and standards you choose to use, it is vital to ensure that everything you are adopting is able to communicate. Some solutions may be better suited to a particular entertainment aspect. For example, it may make sense to employ a Dante network for audio. However, if you’re looking for a solution to control the whole show, MSC could be a simpler, yet all-encompassing, option.