It was long reputed to be the work of Joseph Haydn, but later scholarship suggested that it was actually written by Leopold Mozart. Its authorship is still disputed, however, and other composers have been proposed as the symphony's true author, including Joseph Haydn's younger brother Michael Haydn, who purportedly contributed movements to the work.
Recent research on a newly found manuscript suggests the Austrian benedictine monk Edmund Angerer (1740–1794) to be the author. If Angerer's manuscript is the original, the Toy Symphony was originally written not in G but rather in C. These findings, however, are disputed among scholars. There is reason to believe that the true composer will likely never be known, in whole or in part, given its confused origins and the paucity of related manuscript sources.
- p. 201, Ewen (1965) David. Upper Saddle River, New Jersey The Complete Book of Classical Music Prentice-Hall
- Description by Uncle Dave Lewis. "Toy Symphony (Cassation), for toys, 2 oboes, 2 horns & strings in G major (formerly K. 63) – Leopold Mozart | Details, Parts / Movements and Recordings". AllMusic. Retrieved 2014-08-05.
- Benstock,, Seymour (June 14, 2013). Did You Know?: A Music Lover's Guide to Nicknames, Titles, and Whimsy. USA: Trafford Publishing. p. 194. ISBN 9781466972926.
- "15. Wer komponierte die weltbekannte Kindersinfonie?". Archived from the original on 1 March 2012. Retrieved October 2014. Check date values in: