When it comes to the roles of every rock band, the singer tends to feel like the most amazing job in the world. Since you don't have to hide behind any instrument or drum setup, you can use every minute that you're onstage to give the crowd the greatest experience they could ask for, whether it be strutting around the stage or going for epic vocal runs. Even though there are plenty of perks that come with being the frontman, there's still a lot of care you have to put into your instrument.
Then again, not every difficult vocal line is created equally. While most people think that the hardest vocal lines deal with how high you can go, some of the most difficult songs to reproduce come with trying to harness the same energy that the singer had when they first started out. Hell, some of these aren't so much singing as they are an endurance test, putting the maximum amount of breath support, volume, and raw aggression into the performance to make the crowd go absolutely insane.
At the end of the day though, these are the songs that the rock genre was made for, pushing every part of your body to the limit to make sure you can sell it 100%. It's not necessarily opera, but it still has the same amount of force.
10. The Number of the Beast - Iron Maiden
As the years have gone on, metalheads have come into their own as having some of the more difficult karaoke jams in their arsenal. Since the entire appeal of the music is to be as extreme as possible, it makes sense that you'd want the actual vocalist to follow suit. Then again, when you get a name like the Human Air Raid Siren, fans better stand the hell back before taking on Number of the Beast.
Before you even get behind the actual melody, the sheer power of Bruce Dickinson's voice is enough to keep you on your toes, considering his bellowing register being the benchmark for every other metal band going forward. While everything starts off with a slow and hushed tone, the intro keeps building and building in intensity before giving way to one of the most powerful screams to be captured on a metal release.
This kind of impressive howl is almost impossible to reproduce exactly right, with Dickinson himself not even having the capacity to recapture it when it came time to do a second take. Although a handful of Iron Maiden's hits could make an entire ranking on this list by themselves, the fact that the man himself can't even do this anymore is a testament to them being on a whole different level than their peers.