By default, pianoscope uses a built-in microphone of your iPhone or iPad for recording and analyzing the played tones. If you deactivate this option, you can also use external microphones. An external microphone is not necessary to achieve good tuning quality. However, in extremely noisy environments, an external contact microphone can help avoid interference.

Newer iPhones, such as the iPhone 15 Pro, feature four built-in microphones, while newer iPad Pro models have five. If you activate this switch, pianoscope uses multiple built-in microphones. The app analyzes their signals independently of each other and combines the results. This improves tuning consistency, especially in the case of false beats in the high treble.

If you enable this option, you can also use the microphone of a Bluetooth headset. However, since the audio quality of these microphones is limited, this setting is only recommended for aural tuning with the Tone Generator.

You can read the current level of the audio signal recorded by pianoscope from the level meter. Make sure that the peak does not reach the red area when playing piano notes, otherwise distortion will occur during recording.

Some iOS devices and external audio interfaces allow you to manually adjust the input gain of the microphone. This is useful for ensuring optimal audio quality, as it lets you modify the sensitivity of the microphone to better capture the desired sound source. However, not all iOS devices or audio interfaces support gain control. If the input level slider is disabled, your device or interface does not support gain adjustment.

If you are using multiple built-in microphones or have connected an external multi-channel audio interface, a detail indicator appears in the row with the graphical representation of the input level.

If you tap the row with the input levels, a dialog opens in which you can select which channels pianoscope should use for the recording. If you select multiple channels, the app analyzes their signals independently and combines the results. This improves tuning consistency, especially in the case of false beats in the high treble.

This setting controls when pianoscope disables the analysis of piano tones via the microphone.

Here you can calibrate the absolute pitch measurement in pianoscope against an external reference source. However, the audio hardware of modern iPhones and iPads is of such good quality that calibration is usually not necessary. In our tests so far, we have encountered only a few devices whose absolute frequency measurement deviated by a few tenths of a cent.

For regular use absolute frequency accuracy is rather unimportant, since the perceived sound of a piano tuning depends only on relative frequency ratios. Absolute accuracy is only important when precision is required for playing with other fixed-tuned instruments.

To calibrate pianoscope you need a reliable external tone generator with a known frequency. By default, the calibration view expects a tone of 440 Hz. However, you can set other frequencies by tapping the number.

As soon as you start the external tone generator, a red indicator appears showing how much the measured frequency differs. To calibrate, move the slider carefully back and forth until the indicator is at zero.

If you have no other audio device connected to your iPhone or iPad, pianoscope plays generated sounds through the built-in speaker. However, as soon as you use a headset or an external audio interface, the sounds will be played through them.

Activate this option if you want to use the built-in speaker for playback despite connected audio devices.

Disable this feature if you do not want pianoscope to play sounds through a connected Bluetooth headset.

Enable this option to tune by ear using the tone generator while your device is locked. See Headless Tuning.

Enter the number of the highest partial tone to be generated by the tone generator here. By default, this value is set to 15. You can select a value between 1 and 50.

You can tap a partial bar in the Partials View while the tone generator is running. This selects the partial and makes the tone generator play only that partial. By default, the loudness of the isolated partial remains the same as in the full sound. If you activate the Boost Selected Partials option, the selected partial’s volume is increased so it becomes clearly audible.

If you are using a headset, you can pause tone generation by playing the next lower semitone. However, this only works when playing on a real instrument, not when selecting a tone on the on-screen keyboard. You can resume tone generation by playing any other note.

When you have calibrated the audio input, you can use the calibrated input to similarly calibrate the audio output. With the internal speaker this is rarely needed, but with an external audio interface it may be necessary.

A tone is generated through the audio output and a red indicator appears showing how much the measured frequency differs. To calibrate, move the slider carefully back and forth until the indicator is at zero.