Salutations all, I have been working on a rock inspired Dnd campaign based on some of my favorite classic (and some modern) rock songs/bands. I have come up with most of the major plot points, I just thought I'd ask for some help finding monsters (whether it be home-brew or official). I am mainly in need of help finding some music/sound based monsters, and possibly some mini-boss ideas. Thank you for reading, all help is highly appreciated and I'll try my best to reply to everyone.

Music sound based monsters? you are doing some homebrew so they all can have that ability to be a bard. Sirens are a good initial choice. 

You can also have monsters that hate music or music hurts them because of their hyper hearing. 

Just use monsters from whatever and come up with additional traits that fit the game. 

"You travel down the road and hear music close by. Upon getting closer a group of harpees are jamming away in the night. So you approach?"

Be silly and fun. Your world to create.

I quite like that idea. I definitely will have to implement some of that. I thank you kindly :).

I don’t know if it exists but if nobody else will make it than I will make it cus it’s a good idea.

Speaker golem: it’s somewhere between an iron golem and stone golem in CR. It has a slam attack, and to fit its nature it also has some sound based AOE attacks that can have a chance to deafen or stun. It also has some innate spellcasting for spells with mainly verbal components (ex: vicious mockery, command).

This could be a fun mini-boss or enemy depending on the level of the players you’re dealing with.

Other than that I have some more less thought out ideas:

An angry mosh pit

A bard-fighter enemy with an axe blade attached to a guitar 

A drummer with a drum set where the base is actually a cannon

Sentient drum stick that make multiple weak attacks in one action  

Again I have no idea if any of these or anything close to them have been made, but if no one has or is willing to I could make some of them in my spare time, on guaranties tho.

Love it! A speaker golem sounds awesome as a mini-boss preceding an artificer-type boss. I've also already made an NPC who is a Bard-Barbarian with an axe-bladed guitar. Thank you very much for the advice.

Quote from MagicClockMachine>>

An angry mosh pit

I am imagining this as a gargantuan-base-sized swarm of undead which wraps itself around a target and then moshes the heck out of them until they're down!

Whith then makes me think you need a metal band frontman lich-bard who has the best crowd-control going.

A custom monster I used (against first level PCs, so could use adjustment at higher levels) was dancing skeleton.

There aren't a lot of standard music themed monsters (searching for monsters with performance skill finds lots of custom creatures, but only the bard and satyr in core books). A few other monsters to consider would be banshee, gibbering mouther, harpy, yeth hound.

Quote from ThorukDuckSlayer>>

Quote from MagicClockMachine>>

An angry mosh pit

I am imagining this as a gargantuan-base-sized swarm of undead which wraps itself around a target and then moshes the heck out of them until they're down!

Whith then makes me think you need a metal band frontman lich-bard who has the best crowd-control going.

That sounds awesome! I can already imagine a couple side quest to go along with it. Thank you for the help.

Quote from Pantagruel666 >>

A custom monster I used (against first level PCs, so could use adjustment at higher levels) was dancing skeleton.

There aren't a lot of standard music themed monsters (searching for monsters with performance skill finds lots of custom creatures, but only the bard and satyr in core books). A few other monsters to consider would be banshee, gibbering mouther, harpy, yeth hound.

 Thats a really interesting home-brew monster. Thanks for sharing that and the other monsters.

"a long time ago, me and my brother Kyle here were hitchhiking down a long and lonesome road, when all of a sudden, there shined a shiny demon, in the middle, of the road. AND HE SAID! "play the best song in the world, or I'll eat your souls" so me and Kyle, we looked at each other, AND WE EACH SAID! "okay"" -jack black(with tenacious d) "tribute"

all jokes aside I think this would be really funny

Quote from Capatin_Crunch >>

"a long time ago, me and my brother Kyle here were hitchhiking down a long and lonesome road, when all of a sudden, there shined a shiny demon, in the middle, of the road. AND HE SAID! "play the best song in the world, or I'll eat your souls" so me and Kyle, we looked at each other, AND WE EACH SAID! "okay"" -jack black(with tenacious d) "tribute"

 

all jokes aside I think this would be really funny

 I don't know why I never thought of using 'Tribute'! I love Tenacious D, and that suggestion. Thank you.

Quote from GudranStonejaw >>

 

Quote from Capatin_Crunch >>

"a long time ago, me and my brother Kyle here were hitchhiking down a long and lonesome road, when all of a sudden, there shined a shiny demon, in the middle, of the road. AND HE SAID! "play the best song in the world, or I'll eat your souls" so me and Kyle, we looked at each other, AND WE EACH SAID! "okay"" -jack black(with tenacious d) "tribute"

 

all jokes aside I think this would be really funny

 I don't know why I never thought of using 'Tribute'! I love Tenacious D, and that suggestion. Thank you.

 Wonderboy as a celestial NPC.
Sasquatch as main diamond dealer in the world, used for ressurrection spells
Main political plot - the government is taking all the beautiful animals and making them --- extinct!
A fey NPC who reoccurs, who casts spells on people, called Lee.
Thug gang leader enemy called Larry (Ohh, he's really scary)
Two BBEGs - one is Beelzeboss, who has a weakness. The other is an entity known only as "The Metal".

I made a golem specifically design for annoying bards called the bard-ripper golem. it was a regular iron golem, only no sound could exist within 15ft of it. they were created by The Man so people would watch the MTV puppet shows instead of listening to live performances, because the golems would be strategically positioned around common performance spaces

Quote from ThorukDuckSlayer >>

Quote from GudranStonejaw >>

 

Quote from Capatin_Crunch >>

"a long time ago, me and my brother Kyle here were hitchhiking down a long and lonesome road, when all of a sudden, there shined a shiny demon, in the middle, of the road. AND HE SAID! "play the best song in the world, or I'll eat your souls" so me and Kyle, we looked at each other, AND WE EACH SAID! "okay"" -jack black(with tenacious d) "tribute"

 

all jokes aside I think this would be really funny

 I don't know why I never thought of using 'Tribute'! I love Tenacious D, and that suggestion. Thank you.

 Wonderboy as a celestial NPC.
Sasquatch as main diamond dealer in the world, used for ressurrection spells
Main political plot - the government is taking all the beautiful animals and making them --- extinct!
A fey NPC who reoccurs, who casts spells on people, called Lee.
Thug gang leader enemy called Larry (Ohh, he's really scary)
Two BBEGs - one is Beelzeboss, who has a weakness. The other is an entity known only as "The Metal".

 

 I love it. I'll definitely have to use some of these. Thank you.

Quote from Capatin_Crunch >>

I made a golem specifically design for annoying bards called the bard-ripper golem. it was a regular iron golem, only no sound could exist within 15ft of it. they were created by The Man so people would watch the MTV puppet shows instead of listening to live performances, because the golems would be strategically positioned around common performance spaces

 That is incredible. I love the idea of having The Man as a villain with the golems as accomplices. Thank you kindly.