diff --git a/src/LFO/lfo_freq_sine.m b/src/LFO/lfo_freq_sine.m
index 3fc4273..bef74a5 100644
--- a/src/LFO/lfo_freq_sine.m
+++ b/src/LFO/lfo_freq_sine.m
@@ -5,11 +5,13 @@ function output = lfo_freq_sine(amplitude, frequency, phase, fs, duration, input
 % Neelay Joglekar: Original author
 
 % SOURCES:
-% Code based off of Benjamin Liou's functions (lfo_sine)
-% https://dsp.stackexchange.com/questions/2349/help-with-algorithm-for-modulating-oscillator-pitch-using-lfo
+% Code inspired by Benjamin Liou's lfo functions
+% Code also inspired by Darren and Anne's pitch envelopes
+% Source for frequency modulation equation:
+%   https://dsp.stackexchange.com/questions/2349/help-with-algorithm-for-modulating-oscillator-pitch-using-lfo
 
 % DOCUMENTATION:
-% Frequency is modulated by 20 semitones (20 above, 20 below)
+% Frequency is modulated by sine wave with given amplitude (in octaves, not Hz)
 
     % initialize local variables from input arguments
     n = fs * duration; % number of samples (length of matrix)
@@ -18,12 +20,17 @@ function output = lfo_freq_sine(amplitude, frequency, phase, fs, duration, input
     % create output array
     output = zeros([1, n]);
     
-    x = 0.0; % theoretical input index, assuming input not discrete
+    x = 0.0; % the theoretical input index if the input were not discrete
     % populate output
     for i = 1:n
         t = i * dt; % time at the i'th sample
-        omega_ratio = 2 ^ (20/12 * sin(2 * pi * frequency * t - phase));
+
+        % Increment x based off of sine wave output
+        omega_ratio = 2 ^ (amplitude * sin(2 * pi * frequency * t - phase));
         x = mod(x + omega_ratio, n);
+
+        % Linearly interpolate the actual indicies adjacent to x
+        % to get an output value
         x_0 = floor(x) + 1;
         x_1 = mod(x_0 + 1, n) + 1;
         output(i) = (input(x_1) - input(x_0)) * (x - x_0) + input(x_0);