Sir Karl Jenkins attended King Charles III's coronation but users could not place who he was and called him Meghan Markle in disguise. Some users were convinced that it was Markle "sneaking into" the coronation, despite her being in California with her children, Archie and Lilibet.Numerous social media users took notice of the guest among the crowd of 2,200 people at Westminster Abbey on Saturday. Some argued that the attendee looked like he was covering up his identity.Alis Huws Harpist@alishuwsharpLook who I found at the #CoronationConcert last night! It was such an honour to perform Sir Karl Jenkins’ work, Tros y Garreg (Crossing the Stone) with the Coronation Orchestra on Saturday - he’s truly a living legend! 🏴󠁧󠁢󠁷󠁬󠁳󠁿593Look who I found at the #CoronationConcert last night! It was such an honour to perform Sir Karl Jenkins’ work, Tros y Garreg (Crossing the Stone) with the Coronation Orchestra on Saturday - he’s truly a living legend! 🏴󠁧󠁢󠁷󠁬󠁳󠁿 https://t.co/v0NaNUIbUjThe man in question was seen sporting a mullet and mustache while he sat beside Andrew Lloyd Webber during the ceremony. His look was topped off with a pair of tinted sunglasses that immediately caught the eye of several netizens.The man in the picture is Sir Karl Jenkins, a legendary composer whose work was played during the coronation ceremony.Sir Karl Jenkins was part of the rock band Soft MachineSeveral social media users turned to Twitter to question who the mysterious yet "cool" man was.The 79-year-old composed a piece for King Charles' coronation titled Tros y Garreg, which translates to Crossing the Stone. This piece, which Sir Karl Jenkins describes as "haunting" and "very Welsh" was performed by the coronation orchestra and the royal harpist Alis Huws.As per BBC, the track is part of a concerto that was commissioned by King Charles III over two decades ago, i.e. back when he was the Prince of Wales.Paul Crust@ghosteggsThe evolution of Sir Karl Jenkins. #Coronation133The evolution of Sir Karl Jenkins. #Coronation https://t.co/zcWPI7Nm3LSir Karl was reportedly commissioned by King Charles himself to write music for his coronation ceremony.He was appointed an Officer of the Order of the British Empire (OBE) in the 2005 New Year Honours and a Commander of the Order of the British Empire (CBE) in the 2010 Birthday Honours. In 2015, he was made a Knight Bachelor.In an interview with the BBC, Sir Karl Jenkins said he was "honored" to have a part in the coronation. He added:"It obviously sums up Welsh culture — the harp — and he [King Charles III] has always supported Welsh music."Jenkins went on to say:"I don’t know whether he chose it, but he was happy to have it there. I know he likes it, otherwise he wouldn’t have asked me."He is known for his compositions including Palladio, Adiemus, The Armed Man, Requiem, and more.Twitter users questioned Sir Karl Jenkins' identityHowever, Twitter questioned who the man was and joked that it was the Duchess of Sussex, 41, in disguise. Meghan Markle reportedly stayed back in her home in California with her two children as Prince Harry attended the coronation.Other users were convinced it was Donald Trump attending the event.Michael Burea@MichaelBureaWho dis?28044Who dis? https://t.co/ROwhHLVjABSarcastictvat@sarcastictvatHave I missed something or have we not worked out who this dude is, yet?14721Have I missed something or have we not worked out who this dude is, yet? https://t.co/56G8hpKAiLTrubs @Mr_TrubshaweWait!What?2221241Wait!What? https://t.co/tdUgAbT6aMNick de Semlyen@NickdeSemlyenI refuse to believe that this isn’t one of the Beastie Boys.175191592I refuse to believe that this isn’t one of the Beastie Boys. https://t.co/kYwtdqCWS4Twitter user commented on the rumor that Sir Karl Jenkins was actually Meghan Markle (Image via Twitter/ NoContextBrits)Twitter user compared Sir Karl Jenkins to Donald Trump (Image via Twitter/Joanne60183156)Twitter user commented on Sir Karl Jenkins being the mystery man (Image via Twitter/bcburbridge)Hence, to debunk the myth - the "mystery" man was not Meghan Markle but was Sir Karl Jenkins, a music composer.Various other viral theories surfaced online from Saturday's coronation, including the Grim Reaper showing up and Princess Charlotte being the late Princess Diana's doppelganger.Meghan Markle was not in attendance while her husband, Prince Harry, attended the coronation. He left after the ceremony, to make it to California for Meghan Markle and his son Archie's birthday.