The Ear Training Lab

One of the six strings is slightly out of tune — either sharp or flat.

Click a note label to hear that string, or press Strum All Notes to hear them all in order, low to high. Play All Slowly does the same thing, one note at a time with a pause in between.

Use the − and + buttons under the note you suspect to bring it back into tune, then press Check Tuning.

Toggle Repeat Notes on to keep replaying whichever note you last selected, every 4 seconds, until you turn it off.

Toggle Let Notes Ring on to let notes overlap instead of cutting each other off, when selecting notes or using Play All Slowly.

You can change the tuning and the note sound (acoustic guitar or a pure sine tone) from Settings.