# shower thoughts Published articles for shower thoughts. This is one page of public article previews, not the complete archive. Follow Next page to continue. Summaries are not the original full articles. ## Plotting patterns in music with a fantasy record player DevFeed: [Plotting patterns in music with a fantasy record player]() Original publisher: [Read original article]() Author: Oona Räisänen (noreply@blogger.com) Published: 2020-12-08T21:42:00Z Content type: article Language: en Sources: [Oona Räisänen]() Topics: [Script](), [e-ink](), [3D]() Tags: [3d](), [art](), [audio-media](), [blender](), [computer](), [e-ink](), [experiment](), [music](), [patterns](), [physics](), [plotting](), [script](), [shower-thoughts](), [signal](), [video]() ### AI overview The article explores how a vinyl record's wavy surface pattern can reflect the tempo and beat structure of its music. It describes a script that plots FLAC amplitude into a tempo-based grid and discusses clearer patterns in quantized electronic, pop, and rock music, along with a 3D-rendered fantasy record-player experiment. ### Source excerpt Back in April I bought a vinyl record that had a weird wavy pattern near the outer edge. I though I may have broken it somehow but couldn't even test this because I don't own a record player. *) But when I took a closer look at the pattern it seemed to somehow follow changes in the music. That doesn't look like damage at all. When I played the CD version it became clear: this was an artifact of the tempo of the electronic track (100 bpm) being a multiple of the rotational speed (33 1/3 rpm), and these were probably drum hits! My tweet sparked some interesting discussion and I've been pondering this ever since. Could we plot any song as a loop or grid based on its own tempo and see interesting patterns? (*) I know, it's a little odd. But I have a few unplayed vinyl records waiting for the day that I finally have the proper equipment. By the way, the song was Black Pink by RinneRadio from their wonderful album staRRk. I wrote a little script to do just this: to plot the amplitude of the FLAC into a grid with an adjustable width. The result looks very similar to the pattern on the vinyl surface! Note that this image is a "straightened out" version of the disc surface and it's showing three of those wavy patterns. The top edge corresponds to the outer edge of the vinyl. Later I wrote a little more ambitious plotter that shall be explained soon. Computer-conducted music gives best patterns After plotting several different songs against their own tempo like this it seemed that in addition to electronic music a lot of pop and rock has this type of a pattern, too. The most striking and clear patterns can be seen in music that makes use of drum samples in a quantized time base (aka. a drum machine): the same kick drum sample, for example, repeats four times in each bar, perfectly timed by a computer so that they align in phase. Somewhat similar patterns can be seen in live music that is played to a "click track": each band member hears a common computer-generated time signal ## Pea whistle steganography DevFeed: [Pea whistle steganography]() Original publisher: [Read original article]() Author: Oona Räisänen (noreply@blogger.com) Published: 2015-10-06T22:54:00Z Content type: article Language: en Sources: [Oona Räisänen]() Topics: [Steganography](), [data]() Tags: [acoustics](), [audio](), [embedding](), [measurement](), [physics](), [shower-thoughts](), [signal](), [silly]() ### AI overview The article investigates whether a pea whistle's frequency modulation can carry hidden data. It analyzes recordings and spectrograms, finds that the modulation could fit frequency-shift keying, and describes synthesizing a whistle-like signal with a data-dependent phase modulator and harmonics. ### Source excerpt Would anyone notice if a referee's whistle transmitted a secret data burst? I do really follow the game. But every time the pea whistle sounds to start the jam I can't help but think of the possibility of embedding data in the frequency fluctuation. I'm sure it's alternating between two distinct frequencies. Is it really that binary? How random is the fluctuation? Could it be synthesized to contain data, and could that be read back? I found a staggeringly detailed Wikipedia article about the physics of whistles - but not a single word there about the effects of adding a pea inside, which is obviously the cause of the frequency modulation. To investigate this I bought a metallic pea whistle, the Acme Thunderer 60.5, pictured here. Recording its sound wasn't straightforward as the laptop microphone couldn't record the sound without clipping. The sound is incredibly loud indeed - I borrowed a sound pressure meter and it showed a peak level of 106.3 dB(A) at a distance of 70 cm, which translates to 103 dB at the standard 1 m distance. (For some reason I suddenly didn't want to make another measurement to get the distance right.) Later I found a microphone that was happy about the decibels and got this spectrogram of a 500-millisecond whistle. (HTML5 audio: The sound of a whistle.) The whistle seems to contain a sliding beginning phase, a long steady phase with frequency shifts, and a short sliding end phase. The "tail" after the end slide is just a room reverb and I'm not going to need it just yet. A slight amplitude modulation can be seen in the oscillogram. There's also noise on somewhat narrow bands around the harmonics. The FM content is most clearly visible in the second and third harmonics. And seems like it could very well fit FSK data! Making it sound right I'm no expert on synthesizers, so I decided to write everything from scratch (whistle-encode.pl). But I know the start phase of a sound, called the attack, is pretty important in identification. It's simple t