In times long past, the SCREAMLORDS descended to the bottom-most layers of their ZIGGURATS as GONDWANA fell into decline, in no small part due to the inability of the world to bear their power.
Each layer of the ziggurat contains a phrase of their scream-songs, hidden in the noise of howling monsters or iron hinges squeaking. Woe betide those unable to decipher the song and gain appreciation of ANCIENT GONDWANAN MUSIC, for they will surely rouse the ire of the SCREAMLORD and have naught to defend themselves with.
Layers 1-26 of the Ziggurat- Typical dungeon nonsense, though you can increase your AGMA score by one per level unless the music is just too deep for you
Layer 27- THE SCREAMLORD
On the first round of combat, the SCREAMLORD asks if the PC's are ready. If they do not raise their torches in assent, the SCREAMLORD will give them 1 round to make ready and take the opportunity to gargle some embalming fluid.
Round 2, or possibly round one
The Ziggurat is destroyed utterly as the SCREAMLORD does the soundcheck on his sound-amplifying staff. Those present who are prepared due to deafness, earplugs at least 4 levels in bard or music or AGMA, survive the initial soundcheck, but all others are annihilated with no save
The Round After That- The song itself starts, and you have a number of rounds equal to your ANCIENT GONDWANAN MUSIC APPRECIATION(That's what AGMA stands for) score before you are destroyed. The world comes to an end if the song is completed and the local area is coming to an end around you
Delaying your Demise & saving the world
Breaking the Staff of Amplification buys everyone another round of existence, but also summons 1d30 GONDWANANS who have returned to life thanks to their appreciation of no-frills live vocal concerts. 1d30 of them are POSERS who actually just have an appreciation for hanging out with their buddies, and 1d30 of them are HARDCORE who will turn on the SCREAMLORD if the slightest hint of plagiarism is revealed to them (requiring a D20 roll under your AGMA score, +Cha mod) to pull off. If there is an overlap of HARDCORE and POSER, treat the overlap as the default GONDWANAN.
Cutting the SCREAMLORDS throat or otherwise damaging their body has no effect on sound quality as they have transcended the need for a physical form(they still have a WANT for a physical form as evidenced by the mummified groupies of level 7), but the manager will summon BACKUP VOCALISTS against the SCREAMLORDS will just in case, which will detract from the purity of the solo performance and cause a cumulative 5% chance per round that the SCREAMLORD will abort the song and storm off to sulk, which will cause any GONDWANANS in the audience to riot.
You may also attempt to supplant the SCREAMLORD's dominion via challenging them to a rock off. You must have either a legendary musical instrument or mythical singing skill to stand a chance, and both are almost certainly required to have more than a one-in-a-million chance. However, you must prove your superiority in half the allotted rounds, as doubling down on the amount of rocking is twice as damaging to the frail and mortal world. Your task could be easier or harder if GONDWANANS have been summoned to either appreciate or hate your tunes
Also probably like 15hd or so and nobody can hear anything
There's no way this will make it into a campaign as is