IN THE BEGINNING was the voice, and the voice made music, and the voice was good. But because man is, almost by definition, the animal that will not let well enough alone, the voice was not good enough.

The New Grove Dictionary of Musical Instruments, nearly 3,000 pages of tightly packed words and pictures, is essentially an account of humanity's efforts, through the ages, to improve upon the music-making powers of the human voice -- to make music that is sweeter, louder, more accurate in pitch or varied in tone; to reach notes that are above or below the range of our voices; to produce them more rapidly and arch them through a melody with more grace; to allow one person to makehords or counterpoint and fill with sound a hall that holds thousands of listeners.

It has been an awesome effort; it still is. New instruments are being developed today at an amazing pace, as evidenced in this compendious survey's articles on "Computer," "Electronic instruments," "Sound sculpture" and "Synthesizer" -- articles as complete and up-to-date as could be humanly expected but already obsolescent as they come off the press. The effort to give an orderly account of what has often been a rather disorderly process is also awesome.

Some 400 contributors are represented in signed articles, not to mention the innumerable, unsigned entries of one or two lines. Besides the familiar instruments of Western classical music such as the violin, piano, flute and organ (all treated in articles of epic thoroughness), more than 10,000 non-Western and folk instruments are discussed. Look up an African instrument such as the mbira, and you find that this massive reference work takes nearly five pages to progress from "Mbabi. Drum of the Bangba people of north-eastern Zaire" to the "Mbuwa. Bass panpipes played in the Mishiba panpipes ensemble of the Luba/Songe people of southern Zaire." Between these two entries are 42 others on African instruments that have names beginning with "mb," including nearly three pages on the mbila, which is closely related to the mbira.

A good part of the work on this volume was done in the 1970s in the preparation of the even more wide- ranging New Grove Dictionary of Music and Musicians (hereinafter Grove I), whose 20 volumes have become the world's basic reference on the subject. That was not the end of the Grove phenomenon; a dictionary of American music -- badly needed -- is in preparation, and we may hope to see another edition of the basic Grove before the end of the century. Meanwhile (as predicted when it was published) Grove I has already given birth to a series of handy paperback biographies, including the most popular classical composers (Beethoven, Haydn, Mozart, Schubert and Handel) as well as group profiles of the Bach family, Italian opera composers and the Second Viennese School. Relatively minor revisions were needed for these publications; the subjects are only moderately volatile.

But The New Grove Dictionary of Musical Instruments (or Grove II) is essentially a major new undertaking, not merely a spinoff. This is partly because of its sheer bulk, its hospitality to items for which room could not be made in Grove I. But already, after only a few years, updating has been found necessary. Musical instruments are a subject in constant flux. Not only are new instruments (and revived old instruments) coming into use; new ways are being found to produce musical sounds from existing instruments and new information is constantly being uncovered on old instruments, non-Western instruments and folk instruments.

The article on the harpsichod, for example, which ran an impressive 30 pages in Grove I, has been updated and expanded by five pages in Grove II, with two new names (including the esteemed William Dowd) added to Grove I's list of five contributors. The arpeggione is an obsolete instrument to which nothing significant has happened since Schubert composed a magnificent sonata for it in 1824, when it was brand-new. The one-paragraph article in Grove I (with a photo) seemed perfectly adequate. In Grove II, the photo and the author are the same, but the writing has been tightened, the article has been expanded from 15 to 19 lines, and a two-item bibliography has been added.

THIS IS a fair sample of what has been done in Grove II with material from Grove I. Some articles have been kept unchanged, including a few bearing the name of Sir George Grove, who started the whole massive, still- expanding project more than a century ago. Many have been rewritten, updated and elaborated. A few have been drastically revised, or dropped entirely and replaced. Notable among these is the article on "harmonium," which filled nearly seven pages in Grove I. Grove II has only half a page under that title, but much of the material is covered in a seven-page article on "Reed Organ" which was absent from Grove I.

The primary purpose of The New Grove Dictionary of Musical Instruments, as its name indicates, is to list and discuss all the devices man has found or constructed to scrape, bang, blow and twiddle for the production of music. It does this with extraordinary thoroughness from "a" (either an "obsolete Korean barrel drum" or a "stopped flute ensemble of the Red Dunes Bushmen . . . of south-western Africa") to the "zylinderventil" ("a rotary valve"). But it also contains numerous articles on the performance techniques and practices related to various instruments, the music that has been written for them, the ways composers have found to indicate how they want them played, and the most notable people who have invented, built or played them.

In a more leisurely age, editor Sadie remarks in his preface, the book might "have borne some such title as 'The New Grove Dictionary of Musical Instruments, Ancient and Modern, Western and Non-Western, Art and Folk, their History, their Structure, their Invention, their Makers and their Use.'" In spite of that mouth-filling (and quite accurate) description, it is a work of relatively specialized interest compared to Grove I, which goes into vast areas of theory, biography, history and structural analysis, complete catalogues of the works of many composers, descriptions of notable musical cities and surveys of what can be found in the world's great music libraries. In comparison, Grove II takes one corner of the great world of music and explores it in minute detail. It is clearly a descendant of Grove I, but it has used that landmark publication only as a point of departure. In its specialized area, it has advanced the orderly arrangement of accumulated knowledge significantly beyond what was achieved in its predecessor.

There have been other books labeled "dictionary of musical instruments." Most are picture books with a modicum of text; a few are useful. Not one is remotely comparable to The New Grove. Like the larger compilation from which it took its start, it sets new standards in the field.