So I've begun writing several orchestral pieces (forgive me if I use incorrect names, I didn't study orchestrastion or composition beyond my GCSEs).
When writing a piece, you often change the key part way through to inject some flavour and keep the piece interesting. Should you return to the original key when ending the piece?
I've found that it sounds finished regardless of whether I go back to the original key or stay in the new key to the end. Are there any hard and fast "rules" that say you should or shouldn't return to the original?