"3-Tone Music Input Program"
By Brett Bilbrey, George Moses, and Bob Weber
ARCADIAN 2, no. 7 (May 19, 1980): 62-63.


This BASIC program is accompanied by an in-depth tutorial by George Moses called 
"Music Input Program Plays 3-Tone Music in Basic."  George credits the authors 
of the BASIC program separately as: "Program by Brett Bilbrey, modified by 
George Moses and Bob Weber."


"Music Input Program Plays 3-Tone Music in Basic"
By George Moses

Following is the text-only tutorial of how the "3-Tone Music Input Program" is 
used.  Read the actual tutorial in the "Arcadian" newsletter for all the 
important visual parts of the tutorial that are missing here.


This is line 1 of the BASIC program:

1.123456789012345678901234567890123456789012345678901234567890123456789012345678
9012345678901234567

Line 1 is what is called a "REM" statement. That is, a line number followed by a 
period, then some information. When a period follows a line number, anything 
after the period is completely ignored by the computer. However, anything 
following the period takes up memory space, and if we poke data into these 
memory locations and remember which locations the data occupies, the computer 
can go back and read the data later through the peek function and perform the 
program instructions using this information to play music, do graphics or 
anything you tell it to do. Storing data in the text area of the Bally (memory 
locations -24576 thru -22777) isn't a new idea. It was brought to light thanks 
to Dave Ibach's excellent tutorial on the subject, page 78 Arcadian 1979 [Ibach, 
David. "Using the Bally Text Area," ARCADIAN 1, no. 10 (Sep. 31, 1979): 78.]. 
You can put up to 14 REM statements in this program with exactly 97 numbers 
after the period. Number them 1 thru 14 and don't forget the period. The rest of 
the program follows.

["3-Tone Music Input Program" Program LISTed here]
 
Now get yourself some sheet music and start programming music. See the sheet 
I've included for an example. The columns of four numbers under each note played 
each constitute a chord of three notes (the top three numbers) plus a duration 
input (the bottom number). The duration input allows you to play any length of 
note required by the sheet music. See the note and duration input chart at 
right.

Now, run the program and you'll see the numbers 0; -24573 at the top left of 
your screen. That's the memory location of your first note input to the A voice 
of your sound synthesizer. Put the number of the note you want in voice A and 
hit GO. Then the next memory location will come onto the screen and wait for you 
to input the note value for the B voice, and next you'll input the C voice. 
Then, the fourth input will be your duration value for that chord of notes.

So, there are four inputs for each chord. If a chord has only one note (or no 
notes as in a rest) just input zero into the voices you wish silent. IMPORTANT! 
If you input the same note into the same voice in two consecutive chords the 
result will be one continuous note carried for two beats, or as many beats as 
you wish to carry it out. Often this is desirable, but if you want the same note 
played two distinct times consecutively, then you must switch voices, playing 
the next note in the other register and set the first register to zero or use it 
to play another note in the chord. You'll see some examples of this on the sheet 
music I included. In the second measure you'll see the note C (67) carried out 
for two 16th notes in a row in the same register making it a continuous note, 
while I swapped registers with the B (60) to play two distinct notes 
consecutively.

Now, go ahead and input the numbers in the sheet music going top to bottom on 
the columns under each note. When you get to the end of the first bar your last 
memory location number on the screen should be as noted in the right margin of 
the sheet music 32; -24541. Now, INPUT any number larger than 256 and the 
computer will automatically GOTO 100 and prepare to play the music. Input T. 1 
will make if play the fastest. A larger T will make it play slower. The music 
will play up to the end of your data and stop. This way you can proofread what 
you've input up to that point. The program will ask you to input T again. If you 
want to hear the music again input T and hit GO. But, if you want to resume 
inputting data input zero, hit GO and you'll automatically GOTO line 60 to take 
up where you left off.

[Example of sheet music to Bally BASIC music conversion using the song "With One 
More Look At You" by Barbra Streisand.]

Bally Arcade Note Scale &(16) must equal 49

[Sheet music conversion Chart]

What about correcting mistakes? Simple. Just input the memory location of the 
beginning of that bar and input the data again. Say the first bar was wrong. 
Just HALT the program and type in the beginning memory data like this: Z=0;E=-
24573-Z;GOTO 60 and this will get you back to the beginning of the first bar. 
For this purpose It's advisable to put the last memory readout at the right 
margin of each bar as per the example included. The numbers at the end of the 
first bar would get you set up at the beginning of bar 2 if you were to have a 
glitch there and needed to input the correct data. It is IMPORTANT to proof-
listen to each bar before going on because you cannot input corrections in the 
middle of a song. You can start in the middle, but you have to keep inputting 
data till the end. The Bally looks at two bytes of memory at a time when 
inputting and while you correct one note, you're creating a glitch in one of the 
following notes, so you have to keep rolling to cover up the whole performance 
perfectly.

After you input your last note you should alter line 130 to read the ending 
location to stop the music at the end of data. If you don't you'll get some 
awful sounds when the computer runs out of notes to play. Just halt the program 
and ask the computer to PRINT E+Z-8. The answer will be a negative number. Take 
this number and put it in line 130 in place of the E and Z-8 variables and you 
have a complete program.

Another line you may want to change for convenience is line 100. Once you decide 
the best value of T for that song, just set T equal to that number permanently 
in the line. Also you may want to do the following with line 160 FOR M=1 TO 
2000; NEXT M; GOTO 100. This will give you a five second delay at the end of the 
song and automatically begin the music again.

To save on tape with automatic RUN just get your recorder ready, then type in

NT=1;CLEAR;:PRINT;LIST;PRINT":RETURN;CLEAR;NT=0;GOTO 100

Turn on your tape recorder, then hit GO and watch it list. The listing of the 
REM statements will be mostly question marks, but don't worry. The computer 
understands what they are through the peek command in the program. Any questions 
or new discoveries about this music program will be welcomed by all of us of the 
Bally Users' Group of Michigan at 110 E. North St., Brighton, Michigan 48116.