Why do we need NoteUSD?

[Frodo]

I'm not quite sure I understand your question.

NOTES will be the underlying currency, just like BTS in BitShares. Therefore bitAssets on the music chain will be collateralized by NOTES. The market and price of bitAssets is completely independent from the BitShares chain. That means, that one bitUSD on the BTS chain will have a different price than one "bitUSD" (or noteUSD) on the music chain.
It is just a way to express that the bitAssets are created on the independent music chain.

[sumantso]

Can't NOTEs be used as the underlying currency, like BTS is used in BitShares? It seems to be quite redundant to have NoteUSD and it brings with it its own problems.