Authors and Contributers

I wrote everything this repository contains, excluding the contents within libs/stdlib. I inserted package statements that were not originally present at the beginning of each source file, but all other source code contained there is authored by Robert Sedgewick and Kevin Wayne of Princeton University, and can be found here, which is where I obtained it.

@Drkud created the base sound effect, but I modified it slighty for each variation.

What is this project about?

In 2023, my AP Computer Science A teacher breifly introduced the class to propositional logic in order to give us a better understanding of boolean expressions in Java. One major part of propositional logic we discussed was the construction of truth tables. If you're unfamiliar, truth tables display every possible combination of truth values assigned to the atomic statements in the expression, and what each of those combinations yields as the value of the whole expression.

For example, if you have the atomic statments P and Q, and the proposition P v Q (read as "P or Q"), you can construct the truth table for that proposition like so. First, order the atomic statements alphabetically.

To the right of that, write out the full proposition. Now, count in binary, where T is 1 and F is 0, starting at 0, going to 3 (0b11). The ones place should correspond to the last atomic statement alphabetically, the twos place to the second to last, fours place third to last, and so on. For our example, you should end up with something like this.

Finally, evaluate the expression for each of those combinations of truth values, and write the result to the right. Having done that, you'll have a fully completed truth table.

I observed that sometimes reading out the last column of the truth table creates an interesting rhythm. Each "T" represents a hit, and each "F" represents a rest. Each new row is a new beat. I decideed to write a program that takes in a proposition and plays back the resulting rhythm. I hypothesized that being able to conceptualize a proposition as a rhythm could possibly unlock new intuition into the way propositions work. If not, it still has the potential to create interesting rythyms.

I expanded the scope of the project such that there are four possible scenarios on each beat. Those are: rest, ghost, click, and accent. The new possibilities are ghost and accent, because rest and click are the same two scenarios we already had. Ghost is like a much softer version of click, and accent is like a click with emphasis on it.

The way the program determines the scenario for each beat is by making use of one primary and one secondary proposition. The two propositions must have the same number of possible combinations. If both the primary and secondary propositions are false, there is a rest on that beat. If the secondary is true but the primary is false, it's a ghost. If the primary is true and the secondary is false, it's just a regular click. If both the primary and secondary are true, it's an accent.

How to use it

• Note that the sound effects can be very loud and that you should keep system volume very low when runnning. I like to keep mine around 10% when testing, which allows me to hear everything but doesn't hurt my ears.

First, you'll need to clone the repository to your machine if you want to be able to hear audio.

If you only want to see the visual representation, which I don't recommend, you will need to add the extra command line argument false each time you run the program. This option was put into place so that this program can be run in an online IDE such as Replit or Github Codespaces. If you attempt to use audio in an online IDE, nothing will happen at all.

To run the program, navigate to the base directory of the project if you aren't yet there. Then, run the following command . bash_config.sh. This only works in Bash, so if you are using PowerShell or some other shell, you will need to set CLASSPATH yourself. This only has to be done once unless a new terminal has been opened or if your aliases or classpath have been modified. Once you've worked that out, run main with this template: java Main "[primary]" "[secondary]" [beat length]. Insert your primary and secondary propositions within quotes, and the leangth of one beat in milliseconds. You may also add one extra parameter at the end, false, if you would like the program to run silently and only print a visual representation of the rhythm. Here is an example of a valid execution: java Main "-A v B ^ C > D <> E" "A v B v C v D v E" 100.

If you want to only take the first proposition into account and not include a secondary proposition, you can do so by using SimpleMain. It works nearly identically to Main, but it ony expects one proposition. Here is an example of a valid execution of SimpleMain: java SimpleMain "-A v B ^ C > D <> E" 100.

If you want to use your own sound effects, you can delete the previously existing wave files and replace them with your own, making sure they're named the same as the original files. The shorter the sound effects, the shorter you can make the beat length. In general the beat length should not be any shorter than the length of the longest sound effect.

Finally, If you're trying to create interesting rhythms, just remember that the more complex the propositions, the more complex the rhythms. More complex rhythms allow for the possibility of more interesting rhythms, but also for the possibility of unlistenable rhythms. What I suggest is to experiment by connecting multiple propositions into one using logical connectives. One basic thing this can do is combine two ryhtyms into one. For a basic example, assume you have the proposition A <> B, which gives you the rhythm [true, false, false, true], and the proposition -A ^ B, which gives you the rhythm [false, true, false, false]. You can add these two together like this: (A <> B) v (-A ^ B), which gives you the rhythm [true, true, false, true], the combination of the two rhythms produced by the sub-propositions.