Harry Styles SNL
Harry Styles pushes himself to the limit while performing Sign of the Times on SNL YouTube

Harry Styles impressed during his debut appearance on Saturday Night Live, delivering an impassioned performance of chart-topping single Sign of the Times, but the star himself appeared visibly frustrated after his voice cracked at the end of the song.

Fans and viewers alike have taken to social media to comment on the heartfelt, authentic nature of the 23-year-old's live session, branding the star "brave" for his "raw" delivery.

Performing tracks from his upcoming self-titled album, due for release on 12 May via his own label, Erskine Records, Styles perfectly executed the falsetto moments of his lead track, only to break away in frustration as his voice cracked during its explosive finale.

Clearly upset, Styles bowed his head in disappointment despite applause for the scope of his performance, making a prayer gesture to the crowd as a sign of thanks and understanding.

Jumping to the star's defence, multiple Twitter users called on Styles to focus on the positive aspects of his rendition.

"@Harry_Styles YOU WERE AMAZING PERFORMING TONIGHT ON SNL I AM SO PROUD OF YOU BABY! YOU'RE BRAVE AND CONFIDENT," wrote Simone. A second female fan, Laura, concurred: "Harry sang is heart out. Raw emotion and raspy voice. Amazing. @Harry_Styles #FallonStylesSNL

French fan Lola added "Some little voice crack but you can be proud of you @Harry_Styles! I am! You did it! This performance was incredible! Congrats."

Another fan similarly posted: "@Harry_Styles you did so well cupcake the highnote was perfect don't let anyone tell you otherwise. Don't be sad about the voice crack."

One user, Ramona even celebrated the imperfection, tweeting: "@Harry_Styles your voice crack is my new religion Legend."

Singer debuts Ever Since New York and channels rock icons

No such vocal problems affected Styles when performing guitar-driven ballad Ever Since New York. Comfortable on stage, the new solo star moved far beyond his boy band past.

Styles also channelled his love of British rock icons throughout the show, joining host Jimmy Fallon during the entertainer's rendition of David Bowie's Let's Dance in his opening monologue, and even delivered a cheeky impression of The Rolling Stones' Mick Jagger.

Showing off some of the acting skills that landed him a slot in Christopher Nolan's upcoming war epic, Dunkirk, the Redditch-born musician dressed up as Jagger to take part in a 1977-set edition of Family Feud.

The 23-year-old has been keen to chart a course away from bubblegum pop of his boy band breakthrough – discarding One Direction's X Factor mentor Simon Cowell in favour of signing with Columbia Records last year.

Last month NME quoted reports from industry sources that claimed, "…in marked contrast to One Direction's production by committee, Styles has crafted a set that recalls the regal high-water mark of 1970s British rock, Bowie and Queen in particular".

Further detailing his affinity with British music icons during an interview with BBC Radio 1's Nick Grimshaw on the day of release, Styles said: "I think it's hard to not have influences from what you grew up listening [to], I had a good mix between my mum and my dad, because my dad was into, like, Fleetwood Mac, The Beatles, The Rolling Stones, Pink Floyd, Queen; while my mum was like, Norah Jones and Savage Garden."