Stewart has been noted for the uniquely baritonal timbre of his ringing and sweet tenor instrument, as well as his innate musicality and commanding acting ability. He joined the Metropolitan Opera roster in the fall of 2008. His US operatic engagements include: the Prince ("A Flowering Tree") at Chicago Opera Theater; Cavaradossi, Ismaele, Nadir, Pinkerton and Rodolfo for Michigan Opera Theater; Luigi ("Il Trittico") for the Castleton Festival under the baton of Lorin Maazel; Rodolfo with Opera Carolina, The Orlando Philharmonic, Florentine Opera, New Orleans Opera and Nashville Opera; Narraboth at the Arizona Opera; Radames at the Glimmerglass Festival; and the title role in "Faust" at Atlanta Opera. He has appeared as a featured soloist with North Carolina Opera. Abroad, he has performed Don Jose in South Africa and at the Royal Albert Hall, Pinkerton at Opera North, and was part of Peter Sellars’ acclaimed production of Purcell's "Indian Queen" at the Teatro Real Madrid, Opera Perm and The Bolshoi Opera. In Spring 2012, he made his Covent Garden debut as Hassan in Judith Weir’s "Miss Fortune", a role he premiered at the Bregenzer Festspiele in the summer of 2011. In 2011, he appeared as Lieutenant Pinkerton in Opera North's production of "Madama Butterfly", and in 2012 he became the first black musician ever to top the UK Classical Album Chart, when his album "Noah" reached number one and remained there for 7 weeks. In 2013, he appeared as Don Jose in Royal Albert Hall's production of "Carmen" sung in English. Concert performances include his debut with the Birmingham Symphony with an all-Viennese program. He returned to the River Center for the debut of his new show entitled, “So In Love”, and made his Scottish Opera debut as Don Jose in Bizet's "Carmen". He appeared in BBC Music Ambassador's concert with the Scottish Symphony, and reprised his role as Don Pedro Alvarado in Purcell's "Indian Queen" at English National Opera (debut), returning to Covent Garden as Pinkerton in Puccini's "Madama Butterfly" and making his third tour of the United Kingdom, this time in his new show "In Love Again". In 2014 he appeared as part of the Mid-Summer Opera Concert with the Royal Philharmonic Orchestra at Hampton Court Palace, London.