Musical Opinion, often abbreviated to MO, is a European classical music journal edited and produced in the UK. It is currently among the oldest such journals to be still publishing in the UK, having been continuously in publication since 1877.
In its first year Musical Opinion critically reviewed Brahms' new Second Symphony, and in 1879 his Violin Concerto. The October 1936 issue carried an interview with Rachmaninov and championed the young William Walton as Britain's most exciting young composer. Source