MIDI stands for Musical Instrument Digital Interface, and is one of the oldest standards in audio recording and editing. When you’re working with older digital instruments, or anything else that still uses MIDI, you’ll want an audio interface that will take those old, chunky cables. MIDI was first introduced in 1983 after the idea of standardising music digitisation had been conceived a few years before. As a result, MIDI is well-entrenched and you’ll likely need an interface that can handle it at some stage if you work with audio a lot.Interfacing
An interface can connect to your computer or other hardware in a multitude of ways, from USB and PCI to Thunderbolt and Firewire. You can sort for these different interface types to make sure you’re getting an audio interface that matches the recording and editing set-up you’ve already got. Audio interfaces have a lot of ins and outs and features, and it’s easy to miss the forest for the tree with all these potential capabilities. USB is the most common type of wire used by both PCs and Macs, but more specialised equipment will use more specialised standards. That’s not to say you can’t get pro audio USB interface mixers though, for instance.In/Out
Just as important is the line input type, here you have a choice of TRS 1/4-inch, TS 1/4-inch, and XLR for both line and preamp. Audio interfaces can come with just a few in and outs channels, or dozens of different types, and your specific needs will depend on exactly what you’re using the interface for. A singer-songwriter, for instance, will likely only need a couple of channels, so long as they’re the right type. It can pay to buy ahead of your current needs however, so that you’re not constantly constrained by your equipment and having to upgrade.Keyboards
One contemporary example of musical equipment that still uses the MIDI format are MIDI keyboards and controllers. These machines, some looking like conventional keyboards while others appear more like complicated video game controllers, are currently popular among producers of electronic music.