I have had this book (The Dictionary) on my shelf for a number of years now (as a softcover). And before the current edition (1994), I owned the older edition.
My interest is mainly 20th century serious music, and jazz. Unlike the "Oxford Companion to Music", the Dictionary covers 20th century relatively well. Many obscure composers are listed who are not listed in other books, for example Lebrecht's "Complete Companion to 20th Century Music". As such the Dictionary indispensable for me. The information is more factual (and less opinionated) than Lebrecht's. I particularly like the alphabetic arrangement which allows me to quickly look up someone whose music I have discovered by change, or whose name was mentioned in an article or whatever. The listing of works by each composer is reasonably complete, particularly for well-know composers.
Of course the Dictionary covers more than composers or even 20th century composers. It covers artists (performers and conductors), major works, musical terms and forms, organisations, instruments, venues, etc. And entries are cross-referenced, as one would expect. The Dictionary contains very few illustrations.
There are 12,500 entries in the second edition, so one would not expect a huge depth. You will often need to know more. However, the Dictionary is a comprehensive, detailed, reliable reference work on music, and as such a good starting point for most topics.
