How Distortion Works in Music
One kind of distortion that I loved to apply in my FastTracker II days, and which I don&#x27;t see used all that often, is to flip the sign.<p>In short, FT2&#x27;s sample editor could handle a few common waveform formats, but this was cross platform days and there were a <i>lot</i> of wave formats. These have differnt headers and different structures, but many of them ended up being just a series of samples, either in 8-bit or 16-bit, and at some sample frequency. To deal with this, FT2 added a button that let you reinterpret a waveform as if it was stored signed or unsigned, and one that let you reinterpret as 8&#x2F;16 bit. This let it load a <i>huge</i> amount of sample formats well enough; you&#x27;d fiddle around with those buttons until it sounded right, then you cut the first few millisecs of noise (the file format header) off the front, and done!<p>But turns out that the &quot;reinterpret as (un)signed&quot; button (called &quot;Conv&quot; in FT2) is pretty spectacular for nasty distortion too.<p>Imagine a sine wave. Loaded correctly, it&#x27;ll look like this:<p><pre><code>     +-----------------------------------------------------------------------------+
     |                                                                             |
     |                                                                            X|
     |                  XXXXX                                                   XXX|
     |               X       XX                                                X   |
     |              X          XX                                            XX    |
     |                                                                      X      |
     |           X               XX                                        XX      |
     |                             X                                      X        |
     |         X                   X                                    X          |
     |                              X                                 XX           |
     +-----------------------------------------------------------------------------+
     |      X                        X                              X              |
     |     X                          X                            X               |
     |    X                           X                           X                |
     |                                 X                        XX                 |
     |   X                             XX                      X                   |
     |                                  X                    X                     |
     |  X                                X                 X                       |
     | X                                 XX            X XX                        |
     | X                                  XXXXXX X  XXX                            |
     |                                                                             |
     +-----------------------------------------------------------------------------+

</code></pre>
Imagine this was stored as 8-bit signed. Now, if you reinterpret those bytes as unsigned, it&#x27;ll look like this:<p><pre><code>     +-----------------------------------------------------------------------------+
     |      XX                      XX                              XX             |
     |     X X                      X X                            X X             |
     |    X  X                      X X                           X  X             |
     |       X                      X  X                        XX   X             |
     |   X   X                      X  XX                      X     X             |
     |       X                      X   X                    X       X             |
     |  X    X                      X    X                 X         X             |
     | X     X                      X    XX            X XX          X             |
     | X     X                      X     XXXXXX X  XXX              X             |
     |       X                      X                                X             |
     +-----------------------------------------------------------------------------+
     |       X                      X                                X             |
     |       X                      X                                X            X|
     |       X          XXXXX       X                                X          XXX|
     |       X       X       XX     X                                X         X   |
     |       X      X          XX   X                                X       XX    |
     |       X                      X                                X      X      |
     |       X   X               XX X                                X     XX      |
     |       X                     XX                                X    X        |
     |       X X                   XX                                X  X          |
     |       X                      X                                XXX           |
     +-----------------------------------------------------------------------------+
</code></pre>
Notice how the top half and the bottom half of the sine waves are swapped.<p>Now, I don&#x27;t understand much about DSP and sound and the frequency domain. Better programmers than me have told me that this makes no sense from an audio&#x2F;music perspective. But it sounds pretty cool; you keep a lot of the essence of the original sound, and add a lot of nasty.<p>I once made a VST plugin that does this (it lets you slide the waveform up, wrapping over to the bottom; its only parameter is by how much to slide), but I don&#x27;t think I have it anymore unfortunately.<p>For context, applied to a random bassdrum using 8bitbubsy&#x27;s amazing Windows clone of FT2[0]:<p>- original: <a href="http:&#x2F;&#x2F;neuvostoliitto.nl&#x2F;808_drum_kick_035_21338.wav" rel="nofollow">http:&#x2F;&#x2F;neuvostoliitto.nl&#x2F;808_drum_kick_035_21338.wav</a><p>- distorted: <a href="http:&#x2F;&#x2F;neuvostoliitto.nl&#x2F;808_drum_kick_fucked.wav" rel="nofollow">http:&#x2F;&#x2F;neuvostoliitto.nl&#x2F;808_drum_kick_fucked.wav</a><p>Just sharin&#x27; :-)<p>[0] <a href="https:&#x2F;&#x2F;16-bits.org&#x2F;ft2.php" rel="nofollow">https:&#x2F;&#x2F;16-bits.org&#x2F;ft2.php</a>