MIDI & your Studio
If you think MIDI died out in the 90s then this article should be a good read. If you live and breathe MIDI, you might still find something of interest here.
MIDI (Musical Instrument Digital Interface) really had its day in the 80s when everything seemed to be sequenced and programmed versus actual instruments being played live. That approach is still useful today and surprisingly it's still commonplace when it comes to creating and programming drum parts using many of the great drum sample collections with a good drum-based software synth. MIDI is still an important part of the studio. Here's why:
From a tracking and mixing perspective, MIDI is still utilized to connect various gear for control over DAWs. For example, The Mackie Control Pro control surface uses MIDI over USB to interface with a DAW. That of course allows the user to control various functions within the DAW (faders, panning, FX, etc). Many control surfaces use some sort of MIDI protocol for communication in fact so having some form of MIDI interface in your studio is quite often a necessity.
Composition and arranging: MIDI still functions as a great tool for music composition. When utilized with a sound module or General MIDI tone module you can compose and record a variety of instrumental parts from piano to bass guitar and strings to drums. As a sketching tool it's fantastic since editing of single notes or changing instrument sounds on the fly is all easily accomplished. Don't like the piano sound you recorded with? Easy, just change the patch on the sound module or soft synth to another - even while the project is playing back. You don't have to commit to anything until mixdown.
Another great feature of MIDI is exchangeability and file size. Most MIDI files are tiny, often under 100KB. Very easy to email and exchange with writing partners. If the General MIDI schema is used (basically a format that defines what instrument is on each channel and how the instrument patches are laid out) then you can be fairly sure that your composition and use of instruments will translate to collaborator's system and play back the same.
Beyond the ability to compose and arrange drum parts via a MIDI keyboard that triggers samples through drum trigger programs like BFD, EZDrummer, Strike and others, MIDI can also be used with guitar systems. MIDI Guitar synth's can allow you to record guitar parts via MIDI and obtain a more life-like feel to them than what is typical of such parts performed on a keyboard.
MIDI switching is another typical use of MIDI protocol - various guitar FX processors and patch-changing units are MIDI equipped which allow complex switching operations to be performed with one press of a button on a floor controller. Through this use it's possible to have a rhythm guitar preset without any FX switch via a single button to become a lead guitar tone thick with reverb, delay and other FX that can potentially be derived together from several different FX units all coupled together via MIDI.
The technology may extend back a number of years but be aware, MIDI is alive and well in most studios and certainly in the live performance context. Make sure you don't overlook its capabilities and usefulness in your own studio.