When the new tuning button is tapped, the software will clear out all current tuning data in preparation for creating a new custom tuning. If there is tuning data that you would like to save, you should save it before starting a new tuning, since the new tuning will discard all current tuning data, such as inharmonicity measurements and tuning curve stretch selections. At this point in time, the current tuning will be a no-stretch tuning, which might be just right for tuning a pipe organ, which does not need any stretch.
After starting a new tuning, the software will jump back to the main tuning screen. From there you can manually select the notes you wish to measure. We recommend that you measure C1, C2, C3, C4, and C5. But you can measure as many notes as you like, but measuring an excessive number of notes will not appreciably improve the tuning over just measuring these five notes.