Classic Computer Magazine Archive COMPUTE! ISSUE 8 / JANUARY 1981 / PAGE 110



Arthur B. Hunkins School of Music, UNC-G Greensboro, N.C. 27412

The Visible Music Monitor (VMM) is a unique and remarkable machine language program for the 8K PET/CBM that codes, saves, edits, displays in musical notation, and performs up to four-voice music. Dr. F. Levinson is the ingenious author. VMM is available in both old and new rom versions; it will work with any D/A converter, including A B Computers' new KL-4M. The extensive features of this program are too numerous even to list here; suffice it to say that they are all highly useful and oriented toward the user.

In addition to a nifty "record changer" playback mode, which permits an entire series of arrangements to be performed without user intervention, two features of VMM are particularly notable: one is the user-definable keyboard. The user may define the PET keyboard in any way he likes for convenient pitch entry (a standard default option is also available). The other especially important feature is the extreme ease of editing, which could alone justify use of the system. With such capability one can be a true electronic arranger, trying various alternatives, creating related versions, transposing, deleting and adding segments or measures, adding individual notes, etc. It is all done by editing (using the PET cursor/edit keys) the musical notation on screen.

Both coding system and musical notation are highly abstract, and take some getting used to. Much of this is due to inherent limitations of the PET in keyboard data-entry and character graphics. The notation is oversized; treble and bass staves cover the entire screen and ledger lines cannot be accommodated (upward arrows are used instead!) In other ways too the notation is abstract and sometimes simplified: there are no ties, no beams (only flags for individual notes; flags go in the wrong direction), no rhythmic spacing, no clef signs, "F" for a flat sign, and " = " for natural. Perhaps most difficult to read are the spread-out chords, notated one note after the other, each with a separate stem, with little slashes to show which notes "go together." In most of these cases there are good (computer-oriented) reasons for departure from traditional notation. The idiosyncrasies do, however, affect the legibility and perhaps the usefulness of the system to the arranger. (Preliminary documentation maintains that the difficulties associated with abstractness in coding and notation can be easily overcome.)

Musical limitations of VMM are by and large those of all four-voice synthesis programs currently available. One of these limitations is the lack of amplitude or timbre envelope; loudness and tone color remain constant for each note (most interesting sounds change). Another is the absence of dynamics; all notes are the same loudness, and voices cannot readily change level. (It is theoretically possible to make one voice softer than another, but doing so is not easy, and the procedure is not explained in the documentation.) Finally, there is the omnipresent bugaboo of clicks—in this case, very audible clicks. The chord-by-chord synthesis approach ("Chamberlin-style" music) shared by all software synthesis systems causes all notes to be reinitialized (i. e., "clicked") whenever any chord tone changes. All notes are effectively repeated whenever any note changes. Thus there is no essential independence of rhythm. These limitations, in one form or another, are likely to be with us for some time. Overcoming them will require sophisticated programming, larger amounts of memory, and perhaps additional hardware. They must be overcome, however, for serious creative musicians to become interested in true microcomputer music synthesis.

I leave it to the individual to decide whether the Visible Music Monitor is sufficiently worthwhile to use as a musical arranging/coding tool. Its editing and debugging capability is clearly the most significant feature. Let me reiterate that VMM is a novel and sophisticated system, which should prove lots of fun for the devoted musical hobbyist/arranger. It is a most inventive piece of software, and author Levinson is to be highly commended for a difficult job well done. Cost of the cassette, with its substantial documentation, is a reasonable $29.90.