[3] After this Stansbury's boy soprano voice probably broke as he disappeared from the musical scene until 1819, when he reappears on the concert platform at the Assembly Rooms in Bristol, returning there in June 1820 alongside his sister Emma Stansbury in his own benefit shortly before departing Bristol to take up the post of director of music at the Theatre Royal in Dublin where he made his first appearance as a composer with an overture to 'Life in Dublin'.
[3] In London Stansbury quickly made the transition from orchestra pit to stage, performing as Captain Macheath[6] in Gay's The Beggar’s Opera in August 1828[4] opposite Miss Bartolozzi (who after her marriage found fame as Mme Vestris and William Farren.
Stansbury was Hawthorn in Arne's ballad opera Love in a Village; Warbleton in The Foundling of the Forest, and Trumore in The Lord of the Manor before reprising the role of Macheath.
In January 1829 he was at the Theatre Royal, Covent Garden where he was employed by Charles Kemble[4] as chorus master, composer and musical arranger, in addition to performing on stage.
During this period Stansbury wrote the music for a number of successful songs for Mme Vestris, including ‘The Banners of Blue’, 'Bonnie Scotland, I adore three' and ‘Spring is Coming’.
He composed the scores for various plays including for Shakespeare’s Early Days; Comrades and Friends; The Royal Fugitive; Neuha’s Cave; The Tartar Witch and the Pedlar Boy; Waverley; The Vision of the Bard, and Puss in Boots, or Harlequin and the Miller's Son.
In 1834 he left Dublin to tour the English provinces, appearing as Dandie Dinmont; Hawthorn in Love in a Village; Pietro in Masaniello, and Mr Browne-Derrington in Englishmen in India, among other works.
[3] In 1838 at the Theatre Royal, Drury Lane Stansbury played Rodolphe in William Tell, reprised Beppo in Fra Diavolo, and wrote the music for The King of the Mist.
He was called on at short notice to take over the title-role on opening night in Michael William Balfe’s production of Scaramuccia at the English Opera House, owing to the 'incapacitation' (a contemporary euphemism for 'drunk') of Adam Leffler.
His daughter Mary Ann Georgiana Stansbury (1838-1902) became an actress who, with her husband, the actor Henry Loydall (1830-1903), toured the provinces of northern England and Scotland during the 1860s and after.