Yamaha Motif XF Owner's Manual page 22

HOW THE DRUMKITS ARE MAPPED (ARRANGED)
While GM (General MIDI) drum mapping is useful in the context of allowing
standardized playback of MIDI files, let's face it - the GM drumkit map is
fairly lame in some respects. Very few drummers have a drum kit with six
different toms in it, for example (well, no one that I know of). And when
was the last time you saw a rock drummer arrive with a set of cuicas?
Ditto for referee whistles, who uses those outside of Latin bands?
Sleighbells? C'mon. Okay, I got it off my chest.
Since it seemed more important to include really useful sounds in the kits,
all of the drumkits use a modified GM map. Basically, each kit presented is
a five-piece drumkit - a kick, snare, two shell toms, one floor tom, plus a
hi-hat, a smaller crash cymbal, a ride cymbal, a splash cymbal, a cowbell
and a china cymbal or shank ride cymbal, and a larger crash cymbal. The
drumkits are positioned in the stereo field as the AUDIENCE would usually
perceive them - hi-tom on the right, mid shell tom on the left, floor tom a
little further left. Small crash cymbal is on the right, ride cymbal and large
crash cymbal on the left, china type or shank-ride cymbal on the left,
splash cymbal slightly to the left, cowbell center-mounted on the kick
drum.
This of course assumes that the drummer is right handed, as most
drummers in the world are. If you would like a different perspective (for a
left-handed drummer), you can swap the outputs from Motif XS which
feed your mixer or sound card - take the left output of the XS and put in
the right input, and take the right output of the XS and put it in the left
input.