Z X C V B N M , . /Music Box
Music Box is a program which converts the C-64 into a synthesizer. The keys of the typwriter keyboard are the keys of your musical keyboard, while the control panel of adjustments and switches is controlled by icons on the screen.
Any of the three voices may be played, or more than one voice may be played simultaneously. A total of 96 notes are playable from within Music Box.. Each voice is set in its own key, in one of eight octaves. The currently active key and octave for each voice is listed in the lower right-hand corner of the voice's control panel region.
Finally, due to a bug in Music Box, the mouse cursor will flicker or disappear completely when it is in the top 32 scan lines of the screen. Since there are no icons near the top of the screen, this should not be much of a problem. The mouse cursor is usually visible in that area when it is moving, and it is always visible in other areas of the screen.
The Keyboard
Music is played by pressing keys on the first or second row above the space bar, with the lower row representing a standard keyboard's white keys and the black keys being on the second row. When the program is first entered, all voices are in the key of C, 4th octave (octave 0 is the low octave). But no matter what key is being played, you play the keyboard as if you are in the key of C, and Music Box will automatically adjust for the key each voice is in.
The keys are layed out according to the diagram below. Pressing a key while holding the left shift key will play a note one octave lower, and the right shift key raises the keyboard one octave.
If any voice is commanded (thru keyboard presses) to play a note out of the playable range (C-0 to B-7), no note will be played by that voice, but other active voices will still play any legal notes they are receiving.
Music Box is monophonic: if more than one key (other than shift keys) is pressed at one time, nothing will be played. Also, the keyboard will not respond if the joystick is active. A mouse or other input device may or may not cause this problem.
A D F H J K : ;
Z X C V B N M , . /
Music Box keyboard layout
The Control Panel
Each voice has an identical set of icons, with each region identified in its lower left-hand corner. The icon groups are labeled across the top of the voice 1 region. In addition, the icons controlling the filters are in a region in the lower left-hand corner of the screen, and in the lower right-hand corner are icons controlling miscellaneous functions, such as switching voices on and off and adjusting the master volume. In the lower right-hand corner of each voice's region is the key and octave for that voice, i.e. what note is played when the X key is pressed.
Voice control
Waveforms-- The left-most set of icons controls the waveform. The icons represent, left-to-right, the sawtooth, triangle, pulse, and noise forms. The currently active form(s) are indicated by their icons being inverted. The waveforms start out in "select-one" mode, in which clicking on a new waveform will turn off the old form and turn on the new one. There is also a "toggle" mode available, in which more than one waveform may be active simultaneously. In toggle mode, clicking on a waveform icon toggles that form between the on and off state. Clicking on options in the menu bar opens a sub-menu from which you can change the waveform mode.
ADSR-- The group of four vertical bar graphs in each voice region indicate the status of the attack, decay, sustain, and release registers respectively. "Attack" is the amount of time a sound takes to reach a peak, "decay" is how long it takes to fade from that peak to the "sustain" level (which is synonymous to the volume control for each voice), and "release" is the time it takes for the sound to fade out once the key is released.
To change the value of any of these registers, click on one of the arrows adjacent to its graph to make a minor adjustment, or hold the mouse button down to make a greater adjustment. The up arrow raises the value, the down arrow lowers it, and you can watch the bar graph go up and down to represent the register's new value.
Pulse Width-- The horizantal bar graph represents the pulse width register. Changing this register's value affects the sound only when the pulse waveform is selected. Its value represents the portion of each wave cycle that the pulse is in the high state. This register's value is adjusted up and down by clicking on the left or right arrows, or holding the mouse button down to make any adjustment other than a minor one:.
Filter, Syncronization, and Ring Modulation-- When the square icon with the letter F is turned on, the output of that voice is routed through the filter. Filter adjustments are described below. The icon with the letter S activates synchronization of that voice with the one whose number is printed between the "S" and "M" icons. The M icon affects the sound of a voice only when the triangle waveform is selected, and it ring modulates that voice with the one indicated by the little number. You can experiment with synchronization and ring modulation by changing the key and/or octave of the voices being paired.
Changing key or octave range-- By clicking on the "Voice 1", "Voice 2", or "Voice 3" items in the menu bar, you can change the key and/or octave for that voice. By clicking on "Set key" or "Octave" in the sub-menu, you will get another sub-menu of available keys or octave ranges. The currently selected key or octave range will be marked in the menu with an asterisk. Each octave range begins with a C and ends with a B.
Playing multiple voices and chords-- At program start, the voices are in "select-one" mode, which is similar to select-one mode for waveforms (see explanation under "waveforms" above). By clicking on the 1, 2, or 3 icons near the bottom of the screen, you can change the active voice in select-one mode, or turn voices on and off in toggle mode. These modes can be selected from the options sub-menu.
You can play two- or three-note chords by having that many voices active, and having the keys for each voice set at values corresponding to the desired chord. For instance, to set up a "do-mi-so" chord with voice 1 set in the key of C-4, set voice 2's key to E-4 and voice 3's to G-4. Then as long as all voices are active, each key you press will play the appropriate three-note chord.
Filter controls
Resonant Frequency-- The resonant frequency is adjusted on the horizantal bar graph in the lower left-hand corner of the screen. Use this adjustment to change the cut-off frequency between lower and higher values corresponding to the length of the bar graph. The value is changed in the same way as the pulse width registers described above.
Resonance-- The resonance register determines the degree that frequencies near or away from the resonant frequency are enhanced or subdued. The resonance is adjusted in the same manner as the ADSR registers described above.
Filter Mode-- The L, B, and H icons represent "lo-pass", "band-pass", and "hi-pass" filtering respectively. Lo-pass allows frequencies below the selected resonant frequency to be passed while others are filtered out, hi-pass passes frequencies above the resonant frequency, and band-pass passes only frequencies near the resonant frequency. Clicking on the icon toggles the filter mode on and off.
Other icons
Filter external input-- Clicking on the X icon routes any external input through the filter. This icon is a toggle switch.
Voice on-- The 1, 2, and 3 icons select the active voice. This group can be either in "select-one" or "toggle" mode by selecting the mode from the options sub-menu. Use of these icons is described above under "Playing multiple voices and chords".
Volume-- The master volume is adjusted on the vertical bar-graph in the lower right-hand corner of the screen. See the "ADSR" section for instructions on adjusting vertical bar-graphs.
Future versions of Music Box
Music Box is one of several projects the author of this program is working on, and his enthusiasm for making enhancements and upgrades will be directly proportional to the number of users who send a $10 donation for the use of this program. Please make checks payable to Cary Roberts, and send them to:
Zendik Farm -- Music Box
1431 Tierra del Sol Rd.
Boulevard CA 92005
Features which may be added in the near future include: fixing the disappearing mouse cursor bug; amplitude modulation, frequency modulation, setting the filter cut-off frequency to follow the keyboard, saving register settings and invoking them either by menu or special key presses, and an on-screen metronome.
V 2.0--