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'Un-Break My Heart' by Toni Braxton -

This 1996 R&B tune starts off with a smoky low register. Braxton then delivers powerful, yet controlled vocals that convey a ton of emotion. 

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'How Can I Ease the Pain' by Lisa Fischer -

A slow, breathy ballad not many can sing. And then there's the impossibly high vocal run towards the end of the song. 

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'imagine' by Ariana Grande -

Timing is everything in this song, and so is singing in tune. Not to mention the whistling sounds Grande makes towards the end of the song. This is a great example of a more modern pop song that is really hard to sing. 

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'Don't Rain on My Parade' by Barbra Streisand -

This high-energy song from the musical 'Funny Girl' is a very challenging number. It requires a great amount of breath control and precise intonation.

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'Go the Distance' by Michael Bolton -

This Disney song is all about delivery and conveying emotional depth. 

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'You Raise Me Up' by Josh Groban -

Originally written by the Secret Garden, 'You Raise Me Up' has been covered by many artists over the years. Josh Groban's version of the epic ballad is by far the most challenging one to sing. 

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'Hurt' by Christina Aguilera -

Christina Aguilera simply has to be mentioned. The singer is known for her impressive range and vocal ability. 'Hurt' might not be her greatest hit, but it's arguably her hardest song to sing. 

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'Crawling' by Linkin Park -

Chester Bennington's melodic, gritty, and powerful vocals make 'Crawling' one of Linkin Park's greatest hits, and also one of the most difficult songs to sing. 

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'Love On Top' by Beyoncé -

A number of Beyoncé songs could have made this list, but with numerous key changes and a wide vocal range, 'Love On Top' is perhaps the most challenging one. 

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'Livin' on a Prayer' by Bon Jovi -

This karaoke favorite is a great sing-along tune, but one that is really hard to sing. And if you think the chorus is demanding, try hitting the notes after the key change. 

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'Don't Stop Believin'' by Journey -

Steve Perry's vocals on this rock classic are really hard to emulate. He has power, he has clarity, and he has emotion. 

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'Hello' by Adele -

Adele is one of the most accomplished singers in the world. She has the power to convey emotion in a unique, poignant way. 'Hello' is probably the best example of this. 

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'Take On Me' by A-ha -

Everyone knows this '80s classic, right? And surely, everyone has tried to sing along to it, only to be crushed by the impossible-to-sing chorus. The falsetto and the big leaps of range make 'Take On Me' one of the most difficult songs to sing, even for experienced vocalists. 

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'I'll Never Let You Go' by Steelheart -

Steelheart might not be the most famous glam metal act of the '80s, but their ballad 'I'll Never Let You Go' is arguably one of the hardest songs to sing. Miljenko Matijevic's vocals are second to none. 

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'I Believe in a Thing Called Love' by The Darkness -

Justin Hawkins' use of falsetto made many a rock fan raise their eyebrows in 2003, but the truth is that the song was a hit and it established The Darkness as a legit rock band with an incredibly talented singer. 

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'Chandelier' by Sia -

Sia delivers her most passionate performance in this song. Delivering that level of vocal power, intensity, control, and emotion is not easy at all. 

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'Sherry' by Frankie Valli and the Four Seasons -

Frankie Valli is the king of falsettos and not many singers can make it sound as big as Valli in 'Sherry.' The technical ability required to sing this song earns it a spot on this list. 

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'Total Eclipse of the Heart' by Bonnie Tyler -

The Welsh singer's operatic power ballad starts slowly and grows into an untamed beast. Bonnie Tyler's raspy, powerful vocals take the song to places many people can't reach. 

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'Earth Song' by Michael Jackson -

Michael Jackson has some unique vocal lines, many of which are difficult to sing. 'Earth Song'—particularly the chorus—is one of the most difficult ones. 

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'The Star-Spangled Banner' by John Stafford Smith and Francis Scott Key -

Yes, the US national anthem is one of the hardest ones to sing! With music from John Stafford Smith and lyrics by Francis Scott Key, 'The Star-Spangled Banner' is truly challenging to sing well. 

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'Bridge over Troubled Water' by Simon & Garfunkel -

It's not easy to sing a quiet emotional song like this one. 'Bridge over Troubled Water' is a beautiful and difficult melody to sing.

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'Wuthering Heights' by Kate Bush -

Kate Bush is not your average singer, and this song is a great example of her magnificent vocal range. If you're looking for a challenging song to sing, 'Wuthering Heights' is your tune. 

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'Unchained Melody' by The Righteous Brothers -

The Righteous Brothers popularized this song, which was then covered by many other artists. It remains one of the most challenging ballads to sing due to its emotional charge and high notes. 

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'Dream On' by Aerosmith -

Steven Tyler starts off slow with this epic ballad, only to go into a crescendo and finish with an incredibly high section. 

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'All by Myself' by Celine Dion -

Celine Dion is indisputably one of the greatest singers on Earth. Any of her songs would fit, but her version of 'All by Myself' is probably the best example of how powerful and controlled her vocals are. 

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'Bohemian Rhapsody' by Queen -

Another karaoke favorite, 'Bohemian Rhapsody' mixes a wide range of vocal styles, and it requires a great degree of proficiency to nail them all.

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'And I Am Telling You I'm Not Going' by Jennifer Holliday -

'And I Am Telling You I'm Not Going' is arguably Jennifer Holliday's hardest song to sing. This one is not only about the power and tone, but also the delivery. 

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'Lovin' You' by Minnie Riperton -

Minnie Riperton's whistle notes on 'Lovin' You' certainly make it one of the most difficult songs to sing. 

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'I Will Always Love You' by Whitney Houston -

The iconic ballad, originally recorded by Dolly Parton, became huge when performed by Whitney Houston in 1992 as part of the soundtrack of 'Bodyguard.' Ever since then, it's been one of the go-to songs for singers who want to challenge themselves. 

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'Emotions' by Mariah Carey -

Famous for her range, which covers five octaves, 'Emotions' is classic Mariah Carey when it comes to hitting glass-shattering whistle notes. Many have tried, and many have failed. 

Sources: (Watch Mojo)

See also: The best power ballads of all time

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