The arrival in New South Wales of the 24-year-old Irish musical virtuoso William Wallace was announced in the Sydney Gazette on 14 January 1836:
Mr Wallace, the celebrated violinist, sailed from Hobart Town in the Leda for Sydney, and we understand he intends giving a series of Concerts, in which the first rate musical and vocal talent in the Colony will be engaged. 
Wallace duly gave his first concert in Sydney on 12 February at the Royal Hotel, under the patronage of Governor Bourke. Again, the Sydney Gazette reported in glowing terms:
Mr Wallace's performances throughout were listened to with breathless attention; and his playing struck a peculiar awe into the hearts of his numerous hearers who every moment burst forth with rapturous and enthusiastic applause […] Mr Wallace, we hear, is about becoming a resident among us, for his splendid and novel performance on Friday evening has been hailed as the commencement of a new era in the chronology of music in this Colony. 
That night Wallace played a piano concerto by the Viennese composer Heinrich Herz (1803–1888), as well as, on the violin, a concerto by Josef Mayseder (1789–1863) and Paganini's Variations. The latter performance earned him the local sobriquet, the 'Australian Paganini'. At his second concert Wallace concluded his program with a local gesture, adding 'some extemporaneous variations' of his own to a theme submitted by one of the audience – the song 'Currency Lasses' 'as composed by our talented town's lady, Mrs John Paul senior'. 
In extracting an exorbitant fee for his next concert in March, Wallace was deemed by the hitherto supportive Sydney Gazette to have overstepped the mark:
Five and twenty pounds for a night's fiddling (the sum demanded by Mr Wallace … and received), when people grudge a pound towards securing a House of Assembly, is beyond a joke. 
Wallace next turned to teaching and on 4 April announced the opening, under vice-regal patronage, of the first Australian Academy of Music in Bridge Street, for 'the Instruction of Young Ladies, in Vocal and Instrumental Music'. There the teachers also included his wife Isabella (a soprano), sister Elizabeth (also a singer), and brother Wellington (a flautist). Wallace also opened a retail Musical Repository in Hunter Street, for which he imported pianos, while continuing to perform concerts not only in Sydney, but in Parramatta and Windsor.
He organised Sydney's first ever music festival, to mark the Jubilee of settlement, at St Mary's Cathedral in January 1838. But, having meanwhile separated from his wife, Wallace found that ambition got the better of his business acumen. Soon after the festival, he bade Sydney an ignominious farewell, leaving debts of £2,000.
Wallace later claimed that, travelling on from Sydney, he'd made a whaling voyage in the South Seas, gone tiger hunting in India, made a concert tour of South America, and conducted operas in Mexico. However, his Australian biographer Catherine Mackerras (mother of the conductor Charles Mackerras) doubted the veracity of some of these claims, and described their author as
charming but unprincipled, and his habitual untruthfulness makes it hard to determine the real facts about him.
On the other hand, the composer Hector Berlioz sufficiently believed Wallace's claims to have fought against the Maoris in New Zealand that he repeated the story in his own memoirs.
Wallace's sister Elizabeth settled in Sydney and married another singer, John Bushelle. She died in Sydney in 1878, having in the meantime appeared in the title role in a London revival of her brother's most famous composition, the opera Maritana. Originally staged in London in 1845, it was first performed in Australia in 1849 and remained popular here for several decades. There appears to be no truth in the claim that Wallace was already engaged on its composition during his time in Australia (leading to it sometimes being cited as the first opera composed on Australian soil). More credibly, it was later reported that Wallace had been inspired in composing the opera's most popular number, 'Scenes that are the brightest', by memories, not alas of Sydney, but of New Norfolk in Tasmania.
Wallace's operas have been championed in recent times by eminent Sydney-born conductor Richard Bonynge, who, in 2007 was a guest-of-honour at the special ceremony to unveil a new memorial to Wallace at his gravesite in London's Kensal Green Cemetery. Bonynge and his wife Joan Sutherland also made a noted recording of the Maritana aria 'Scenes that are the brightest'.
James Hall, 'A History of Music in Australia', The Canon 4/5, November 1951, pp 152–56
Catherine Mackerras, 'Wallace, William Vincent (1812–1865), Australian Dictionary of Biography, vol 2, Melbourne University Press, Melbourne, 1967, pp 567–568