Douglas Kinnaird [q. v.] to Lord Byron, and thus commenced a friendship which was only dissolved by the death of the poet. At Kinnaird's suggestion Byron wrote the ‘Hebrew Melodies’ for Nathan to set to music, and Nathan subsequently bought the copyright of the work. He intended to publish the ‘Melodies’ by subscription, and Braham, on putting his name down for two copies, suggested that he should aid in their arrangement, and sing them in public. Accordingly the title-page of the first edition, published in 1815, stated that the music was newly arranged, harmonised, and revised by I. Nathan and J. Braham. But Braham's engagements did not allow him to share actively in the undertaking, and in later editions his name was withdrawn (cf. Pref. to 1829 ed.). The melodies were mainly ‘a selection from the favourite airs sung in the religious ceremonies of the Jews’ (cf. Nathan's ‘Fugitive Pieces,’ Pref. p. ix, ed. 1829 p. 144; cf. advertisement by Byron in his collected works, London, 1821). Lady Caroline Lamb [q. v.] was also among Nathan's friends, and wrote verses for him to set to music. In 1829 he published ‘Fugitive Pieces and Reminiscences of Lord Byron … together with his Lordship's Autograph; also some original Poetry, Letters, and Recollections of Lady Caroline Lamb.’ Despite Nathan's claim to long intimacy with Byron, Moore avoids mention of him in his ‘Life’ of the poet. A note affixed to the earlier editions of Byron's works stated that the poet never ‘alludes to his share in the melodies with complacency, and that Mr. Moore, having on one occasion rallied him a little on the manner in which some of them had been set to music, received the reply, “Sunburn Nathan! Why do you always twit me with his Ebrew nasalities? Have I not already told you it was all Kinnaird's doing and my own exquisite facility of temper?”’ (see Notes and Queries, 6th ser. 1884, ix. 71). Nathan's ‘Fugitive Pieces’ gave him a wide reputation, but the success of the volume was not sufficient to keep him out of financial difficulties. He contracted a large number of debts, was compelled to quit London, and for a time lived in retirement in the west of England and in Wales. On returning to London he was advised to appear on the stage in an attempt to satisfy his creditors. He accordingly made his début in the part of Henry Bertram in Bishop's opera, ‘Guy Mannering,’ at Covent Garden about 1816. His voice was, however, too small in compass and strength to admit of this being an entirely successful experiment, though his method was declared by competent judges to have been decidedly good. As his next resource he essayed opera writing, and several operas, pantomimes, and melodramas of his composition were produced at Covent Garden and Drury Lane Theatres, one or two of which obtained a certain amount of favour. Among them may be mentioned ‘Sweethearts and Wives,’ a comedy with music by Nathan and libretto by James Kenney [q. v.], which ran for upwards of fifty nights after its production at the Haymarket Theatre on 7 July 1823. It included two of Nathan's most popular songs, ‘Why are you wandering here?’ and ‘I'll not be a maiden forsaken.’ Nathan's comic opera, ‘The Alcaid, or the Secrets of Office,’ the words also by Kenney, was produced at the Haymarket on 10 Aug. 1824. Nathan's musical farce, ‘The Illustrious Stranger, or Married and Buried,’ the words written for Liston by Kenney, was first given at Drury Lane in October 1827 (see Cat. Sacred Harmonic Soc. Library, 1872, p. 95).
In 1823 Nathan published ‘Musurgia Vocalis: an Essay on the History and Theory of Music, and on the Qualities, Capabilities, and Management of the Human Voice, with an Appendix on Hebrew Music’ (London, 4to), which he dedicated to George IV. The issue of an enlarged edition was begun in 1836, but of this only the first volume seems to have appeared. Contemporary critics considered the work excellent (see Monthly Review, June 1823; Quart. Mus. Rev. vol. xix.; Révue Encyclopédique, p. 156, October 1823; La Belle Assemblée, July 1823). Nathan also gave to the world a ‘Life of Mme. Malibran de Beriot, interspersed with original Anecdotes and critical Remarks on her Musical Powers’ (1st and 3rd ed. London, 1836, 12mo). He was appointed musical historian to George IV, and instructor in music to the Princess Charlotte of Wales.
In 1841 Nathan emigrated to Australia, because, it is said, of his failure to obtain from Lord Melbourne's ministry recognition of a claim for 2,326l. on account, he asserted, of work done and money expended in the service of the crown. The precise nature of the work is not stated by Nathan, but his treatment at the hands of the ‘Melbournitish Ministry’ weighed heavily upon him. The odd 326l. was paid him, but the remaining sum was disallowed (Notes and Queries, 6th ser. ix 355). The matter is fully dealt with by Nathan in ‘The Southern Euphrosyne,’ pp. 161–7, though again the precise nature of the business is omitted. He first took up his abode in Sydney at 105 Hunter Street, but later removed to Randwick, a suburb of that city; and there, and indeed in the entire colony, he did a great deal to benefit church