Ash:
1) Yes, you may add other sound effects/voices, as long as they abide by the Official Rules (i.e. no sound effects/voices from other IPs, but you can make them yourself).
2) Please read the Official Rules, which you can find located below the contest entry form. Here’s the relevant passage in the How to Enter section : “During the Contest Period, to enter, create a music video no longer one (1) minute in length.”
You might also want to review the information under the Video Restrictions section, where it states: “Sponsors reserve the right to allow for minor fluctuations between the Video length limitation stated herein and the actual length of a Video submitted in this Contest, as well as other minor deviations from these Official Rules, based on clear intent to comply with these Official Rules, as determined by Sponsors in their sole discretion” (emphasis mine).
I would strongly advise you to stick within the time limits set out in the Official Rules.
Vetch/Rous:
The contest rules were not changed. The page has remained the same since it went live. It sounds like you initially did a cursory reading of the official rules, and upon a subsequent review, you saw a passage that you missed when you read them the first time.
