Connect an audio interface to your computer. This calls for either a single USB or single FireWire cable, depending on the model of the interface. The interface converts the audio from the microphone to data, so the audio interface can interpret it. Typical audio interfaces are USB-powered, meaning you don't need to plug them in.
Plug an XLR cable into a microphone. Plug the other end into the "Input" socket on the audio interface.
Launch a digital workstation, such as Pro Tools. Typically you double-click the program's desktop icon.
Create an audio channel. The process varies slightly according to which program you use but you typically do this via the "File" menu or a shortcut tab.
Name the audio channel according to the musical sound you intend to record. For example, "Heavy Guitars."
Fit the microphone into a microphone stand. Position the microphone so it is best-placed to record the sound. For example, if recording piano, point the microphone toward the center of the back of the instrument.
Audition the microphone. Play the instrument as loud as you intend to do so when recording. If the volume unit meter on the audio interface flashes, the input level is too loud. Reduce the "Gain" setting until the flashing stops. Aim for the loudest possible gain setting you can get without making the meter flash.
Hit "Record" and play a sequence of single notes, to include every note on your instrument. Leave a gap of two seconds between each note.
Hit "Stop." The recording will appear as a sound wave graphic on screen. This contains a sequence of flat lines and peaks, to represent silence and sound.
Open the "Trim" tool and click the cursor in the spaces between the notes, as close to the edges of the peak as possible for a clean cut. This separates each note in the recording into separate audio files.
Save each separate file and name it according to the instrument and note. For example, "Electric Guitar, Middle C."
Record the same sequence of notes, but use a different sound or style. The objective of making programmable music is to build a library of authentic sound samples. While sound and style are a matter of preference, aim for a combination that makes the sample easy to program. For example, it should be clean with as little embellishment as possible. This means next time you want to sequence a guitar melody via MIDI, you have access to an archive of real-sounding programmable music.