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The FATpick Blog

FATpick is an interactive, animated, side-scrolling tablature viewer that listens as you play along with a real guitar (or bass, or ukulele, or other plucked string instrument) to provide instant feedback on the timing and accuracy of your performance.

To offer this feedback, FATpick employs a sophisticated audio analysis engine to extract pitch, polyphony, onset/offset and related information - in near real-time - from the audio input stream.

FATpick works with any type of guitar - electric, acoustic, electroacoustic - and virtually any audio input device that your computer will recognize. You can connect your guitar directly to your PC using a guitar-to-USB cable (like a Real Tone Cable) or an audio interface (like the Focurite Scarlett line) if you have one. But you can also use a standard built-in or external microphone to capture the sound - the actual, ambient, waves-over-air sound - of your guitar.

Here are some tips, advice, and general guidelines on how to improve the accuracy of the note detection algorithm and troubleshoot the common causes of problems with note recognition.

General Tips for Improving Note Recognition

  1. FATpick works best with a "clean" audio signal, so:

    • Disable any unusual amplifier or pedal effects.

    • Avoid distortion from extreme volume settings, whether in your guitar, amplifier, mixer, microphone or computer

    • When using a conventional microphone, minimize background noise.

    • Eliminate any source of electrical interference that might create a hiss, buzz or hum.

  2. FATpick works best with an isolated audio signal - i.e, when your instrument is the only (or primary) sound that FATpick can "hear".

    • If possible, use a wired, electronic connection between your guitar and your computer rather than relying on a conventional (real audio) microphone. E.g., use a guitar-to-PC adapter cable (with a 1/4" guitar jack on one end and a USB or AUX plug on the other) to connect the guitar output directly to the computer input; or plug your guitar into an analog-to-digital audio interface (and the audio interface into the computer) to form an indirect but continuous signal chain from your guitar to your computer. This will help separate the instrument's audio signal for other sounds (compared to a microphone)

    • Even when using a mic, try to isolate the sound of your instrument as much as possible. For example, position the microphone to primarily capture the sound coming out of the guitar or amplifier rather than the ambient sound in the room.

    • When using the microphone as an input source, use headphones (rather than speakers) to play the audio coming out of your computer.

  3. Keep in mind that the digital audio signal that is being fed into your computer may contain artifacts that are either not found in or not easy to detect in the ambient sounds reaching your ear. Electrical interference or feedback may introduce a persistent buzz or hum that only exists within the electronic audio signal. A little air flow can be overwhelming loud through the microphone while being virtually inaudible outside the mic pickup. Input levels that are turned up too high can introduce "clipping" in the audio signal. Use the monitors, gauges, and meters found within the app to detect these "silent" problems. For example the chromatic tuner tool includes both a spectrogram (signal intensity by frequency) and oscilloscope (audio level over time) -style visualization in addition to the conventional tuner needle.

  4. Use appropriate volume and mic-sensitivity settings. If the input signal is too loud (too strong) it may be distorted or clipped. If the input signal is too quiet (too weak) FATpick won't be able to hear your instrument clearly. You generally want to see the input level meter (as seen on the tab player or in the audio settings menu) to almost but not completely fill the available space - shoot for a level around 60% to 80% full when playing your instrument at normal volume.

    Note that there are at least two mic sensitivity controls that are relevant: (1) the application-level input volume sensitivity slider found under FATpick's audio settings menu and (2) the OS-level input volume sensitivity slider found under in the Windows "Control Panel" or macOS "System Preferences". There may be additional (hardware-level) volume and input level controls found on your external microphone or audio interface device.

  5. Try to tune your guitar (or at least test/validate your tuning) using the in-app guitar tuner. Since this tuner uses the same pitch detection logic as the tab player you can use it to perform a "sanity check" to confirm that FATpick is hearing your guitar properly and that the pitch detection is working in at least the most basic form. Also sometimes you can get slightly different results from two different guitar tuners, so depending on how you are otherwise tuning your guitar the tuner found in the app itself may help you make small adjustments to your tuning that help FATpick interpret your guitar as more precisely in-tune.

  6. Sometimes the reason for a missed note isn't the pitch of the note that you played, but the timing. I.e., if FATpick thinks the note was struck too early or too late it may flag a note as "missed" even if it detects that right pitch. The default/out-of-the-box timing detection usually works pretty well but can be improved via a process known as "latency calibration". This is a quick and easy process that may improve the accuracy of the timing detection and, indirectly, the pitch detection as well. To do this, open the settings menu (cog icon in the header), select "Calibrate Latency" from the menu and follow the on-page instructions.

Also See

These guidelines describe several of the most important factors that influence note detection accuracy and the most common causes for note recognition problems. But they barely scratch the surface of the topic at large. Here are a few related articles that provide additional information or describe some of the more advanced ways to optimize FATpick's note detection.

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