Charles Wheatstone's earliest interests were musical: in his days spent at his father's music shop at Pall Mall, London, he would have been exposed to musical instrument manufacture and since the Wheatstone family business was substantially concerned with both woodwind and stringed instrument manufacture, it is likely that young Charles would have access to both tools and materials, and would have been encouraged to take an interest in his father's profession.
In 1818, when aged just sixteen, Charles Wheatstone produced his first known new musical instrument, the 'flute harmonique', a keyed flute of some kind. Charles Wheatstone's youth in general was much involved with science.
In 1822 he set up the Acoucryptophone or 'Enchanted Lyre' at father William's shop in Pall Mall. This acoustical trick featured an ornate lyre suspended via a thin steel wire from the soundboards of pianos and other instruments in the room above, and which appeared to play 'of itself' by sound conduction and sympathetic resonance of its strings. Charles Wheatstone even purported to 'wind-up' the Lyre when presenting the show! He speculated publicly at this time on the future transmission of music across London and of it being 'laid on to one's house, like gas'. Later, in 1824, he published 'The Harmonic Diagram', a musical theory teaching aid.
Charles and his brother William took over their uncle Charles's musical instrument business on his death in autumn 1823, when Charles was 21 and William about 18 years of age. Charles was clearly well versed in musical theory, having he published his 'Harmonic Diagram' in January 1824.
By 1829, Charles and his brother William had moved their business to new premises at 20 Conduit Street, near Bond Street, Regent Street and Hanover Square. Charles Wheatstone and William appear to have maintained their father and uncle's trade in woodwind and of general musical instrument sales and manufacture.
Charles Wheatstone was interested in musical instruments and their acoustics throughout his life: Parallel to these musical researches, Wheatstone was working variously on typewriters, electromagnetic clocks, pitch measuring devices, and of course, the concertina and its prototypes and improvements, as well as the electric telegraph which became his major life's work. There was no period in his life when he concentrated on just one particular subject, and throughout his life he constantly returned to work on various improvements to the concertina and related free-reed devices.
Wheatstone contributed to numerous scientific journals and publications. All his published papers were collected in one volume and published in 1879 by the Physical Society of London.
Original sources;
Neil Wayne - The Concertina Musium, Belper Derbyshire
Obituary notice in Proceedings of the Royal Society of London, 1876, xxiv, pp. xvi-xxvii; Nature, 1876. xiii, 501, App. p. xxvii ; Extracts from the Private Letters of the late Sir W. F. Cooke, 1895 Fahies History of Electric Telegraphy, 1884; Obituary Notice, Telegraphic Journal 15 Nov. 1875, iii .252.