All instruments are stereo.

Many of the guitars have different styles of playing (ie, articulations). For example, the LesPaul electric guitar has both sustained and muted notes, hammer on/off, harmonic, and some percussive effects. Each articulation is available in a separate sfz file. For example, the LesPaul has 4 sfz files named lp_sus.sfz, lp_mute.sfz, lp_harmonic.sfz, and lp_noises.sfz for the sustain, muted, harmonic, and percussive articulations, respectively. (The hammer on/off articulation is included in the sustain articulation).

Files with a short, nondescriptive name, usually a capital letter followed by a number such as S1, S2l, N1, etc, are not to be used directly. They're support files.

Often, you want to switch articulations for a given instrument. In order to switch articulations on-the-fly, you normally need to load the sfz file for each articulation, and set it to a different MIDI channel. When trying to play and switch articulations live, it can be inconvenient to deal with multiple sfz files, and multiple MIDI channels. For this reason, NBO instruments that offer multiple articulations have a single sfz file which loads all the articulations, and uses MIDI controller messages (usually "Sound Variation" controller, or CC number 70) to switch articulations. This sfz has the word "full" in the filename. For example, "lp_full.sfz" loads all of the aforementioned LesPaul articulations. To switch between the articulations, you use a "Sound Variation" controller as so:

Sound Variation with value 0.	Normal sustain, no vibrato.
Sound Variation with value 1.	Normal sustain, with vibrato.
Sound Variation with value 127.	Hammer on/off, no vibrato.
Sound Variation with value 126.	Hammer on/off, with vibrato.
Sound Variation with value 2.	Muted.
Sound Variation with value 3.	Harmonic.

Noise articulations are automatically added at random, for added realism.