You might sometimes want to have multiple versions of the same instrument to either play different patterns, timing, or amplitude. For e.g. I would love to be able to play a drum n bass sound that has 2 snares:
CH x-x-|x-x-|x-x-|x-x-
SD ----|---x|-x--|----
SD ----|x---|----|x---
BD x---|----|--x-|----
Perhaps we can have multiple entries of the same instrument with different parameters.