there is no such thing as an azure flute in emerald, only in diamond
Blue Flute - Awakens sleeping pokemons
The blue flute wakes up sleeping pokemon
migrate it from emerald
You can acquire a Blue Flute in Pokémon Emerald Version by travelling to Route 113 and walking 250 steps in the ash grass. Then, go to the house which is along the route and talk to the man inside. From there you can get the Blue Flute.
you can use it to awaken your pokemon in battle
It can repel wild Pokemon upon use.
you can't get the black flute in leaf green but you can in Pokemon ruby, sapphire and emerald then trade it to leaf green.
No it doesn't exist.
No, many people say it does, but trust me, don't make the mistake of gathering all of those ashes for the flute like i did, it will not help you in any way to get arceus.
If you Pokemon is infatuated by your oppenent you can use this in battle to stop your Pokemon from being infatuated.
There is no specific time or month to get the Azure Flute from Mystery Gift because Nintendo has not announced the Azure Flute for distribution currently.