Well, I'll tell you what I have seen in the past few years:
One entry was 4min 43sec, and the judges' panel said "Close enough."
The other one that made it (during another year, with a different collection of judges) was MUCH longer, but in the panel's opinion the creator did indeed hold the audience attention for the entire span. It was a game-character trailer style with four main combatant characters, each with a kind of 'familiar' from an alternate, combat-based plane, and then an overview of some of the major bad guys and bosses they had to knock over in the game. So the creator introduces eight characters, illustrated the unique boosts that each character gets when fighting tag-team with his familiar or spirit-warrior aide, and wham/bash/flash/flame/boom/Ki-Aiiiiiiiii/KA-BANG! End titles. Golden AMV.
Why they said this worked was:
- the series was new and not well known at the time. New, fresh faces and costuming!
- the combat scenes showed unusual manoeuvres, weapons effects, spells etc,
- the music was up-tempo, energetic, and often powerful and positive in feeling. No cuss words or tiresome, ear-grating singing styles. Nothing about the music or the message of the AMV would disengage or offend any discernible slice of audience. That said, the audience loves a good thrill, and so 'menacing' can also be exciting.
- one judge's quote "Even 5 minutes in we felt like only two minutes had elapsed. This was exciting the whole way through.
So, yes anything you send to the next year's judges' panel WILL get submitted - even if it's long.
But if you want to cut things down, try using an audio editor program and snip out one exact verse in the song. Usually a middle verse can go and no one will notice. Otherwise, you should be sure you are using ALL stanzas WELL - fitting the lyrics to the scenes we are seeing.
PS I am privately working on a project to Gordon Lightfoot's "Wreck of the Edmond Fitzgerald" and have cut down 6min 36 sec to under 4 min so far, by cutting and matching lyrics and phrases. In my first AMV I trimmed about 8 minutes of movie dialogue down to a 4min 40sec work. It took second place in the contest I submitted.
Anyways GLAD TO SEE you say it's gonna be AMAZING - good luck to you and MAKE IT ROCK!