Yamaha RX21 Owner's Manual page 22

IMPORTANT:
If you switch from a higher quantize rate to a lower one, only the notes occuring
on the new beats will remain—all other notes will be cleared. For example,
if
you have programmed a part at a quantize rate of 1/32, the Beat Exchange
function will switch the quantize rate to 1/16, and all notes which originally
appeared on beats 2, 4, 6, 8 etc. will be erased. This will affect all instruments
QUANTIZE AT 1/32
new dot display
remove them.
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