diff --git a/bin/hz.py b/bin/hz.py
new file mode 100755
index 000000000..3cea4bacb
--- /dev/null
+++ b/bin/hz.py
@@ -0,0 +1,53 @@
+#!/usr/bin/env python3
+# https://click.palletsprojects.com/en/8.1.x/arguments/
+# https://click.palletsprojects.com/en/8.1.x/options/
+
+import click
+import math
+import sys
+
+# I'm not proud (I am a little bit?).
+PROOF = [] # :)
+
+class AgoraCmd(click.Command):
+    def format_help(self, ctx, formatter):
+        click.echo("""Usage:
+        - Visit anagora.org/hz to execute this file in the Agora of Flancia.
+        - Visit e.g. anagora.org/hz/523 to test which note 523hz is the closest to (should return C5)
+        - In general visit anagora.org/foo, anagora.org/foo/bar to execute e.g. <bin/foo.py bar> from your garden.
+        """)
+
+    def __call__(self, *args, **kwargs):
+        try:
+            return super(AgoraCmd, self).__call__(
+                *args, standalone_mode=False, **kwargs)
+        except click.MissingParameter as exc:
+            exc.ctx = None
+            exc.show(file=sys.stdout)
+            click.echo()
+            try:
+                super(AgoraCmd, self).__call__(['--help'])
+            except SystemExit:
+                sys.exit(exc.exit_code)
+
+@click.command(cls=AgoraCmd)
+@click.argument('freq', type=click.INT)
+def hz(freq):
+    """Calculates the closest note to input hz :)"""
+
+    A4 = 440
+
+    # Number of half steps away.
+    n = 12 * math.log2(freq / A4)
+    n = round(n)
+
+    notes = ["A", "A#", "B", "C", "C#", "D", "D#", "E", "F", "F#", "G", "G#"]
+
+    note_index = n % 12
+    note = notes[note_index]
+
+    click.echo(f"hz({freq}) is {note}.")
+
+
+if __name__ == '__main__':
+    hz()