MUSIC is a big subject, and only a keen and erudite student can profess to be well acquainted with fifty per cent. of the works broadcast in an average week. Yet nobody wants to limit his musical appreciation by unfamiliarity with the characteristics of the music that he is going to hear. Mr.Ernest Newman 's weekly talks form an invaluable guide to the broadcast music of the next week, for ho is not only one of the most trenchant but one of the best-informed of music critics.