A keygroup is exactly that -- a group of keys! Making a sample is only half the story. Once you have a few samples, you need to map them out across the keyboard. This is done by assign each sample to a keygroup. The
keygoup has a specific lower and upper note range and sets the range on the keyboard over which the sample will play. For example, with five piano samples taken at G of every octave, you would have 5 keygroups spanned
between C0-B1, C2-B2, C3-B3, C4-B4, C5-G8. The same would be true of any multi-sampled instrument. Drums, however, often have a keygroup for each note so that every drum is on a different note on the keyboard (i.e. Bass/Kick drum - C1, Snare 1 - D1, Snare 2 - E1, LoTom - F1, LoTom - G1, HiTom - A1, etc.).