Yamaha SY99 Owner's Manual page 52

In this way, record all the tracks of the song. As you record each track you will
hear the previously recorded tracks play back. The multi we created in the
beginning of this example uses the following voices.
Multi channel
1
2
3
...
16
With the initial settings of the sequencer, tracks 1-16 will transmit their data on
channels 1-16 (this can be changed) and be received by channels 1-16 (this
cannot be changed) of the multi. If you are following this example, record the
piano on track l, bass on track 2, and strings on track 3.
Voice number Voice name
P1-A03 AP|Concert
P2-C06 BA|Upright
P1-C15 ST|Quartz
P1-D14 DR Kits
41