Music summoning boss battle

We should have a minecraft boss that we summon with a special disc that makes some cool boss battle music.

We only have 2 boss battles and non of them have  special boss battle theme song. Also once the ender dragon and wither is killed there isn't much exploring to do sometimes. So I thought it would be cool that once we kill the ender dragon and the wither there is a new boss you an fight. 

So it would be cool if we mixed all of these ideas for a new cool boss. To summon this boss you need to collect disc shards that you get from fighting bosses, crafting, trading, or looting underwater monuments or other things. It would add more to the game because once you get 1 disc per boss and you kill the wither and the ender dragon you get 2 discs. This will add more to the game once people kill these two bosses. Also it will make you want to explore to find the new disc pieces.

Finally once you have all the disc shards you have to find an ancient ruin that maybe you have a magical compass or you could through the disc shard and they lead you there. Once you arrive at the ruins you can combine the disc shards. Then you could put the disc in a jukebox and it will summon the boss. 

Once the boss is killed you can't summon the boss with the disc again it can play the boss battle theme song but it won't summon the boss. You have to find at least one disc shard (depending on how broken the disc will be) and go back to the ruins to fix the disc again and re summon the boss.