Click the Flag. Enter the code for the G♭ (or F♯) you want. See how well it works with the tune. Repeat for the other options. Post results in the comments.
The tune is Example 26.36 from W. A. Mathieu's book, Harmonic Experience. He mentions many possible tunings of the G♭: 64:45, 45:32, 7:5, 11:8, 25:18, and √2:1. This project is to test which it is. I highly recommend Harmonic Experience if you are interested in music.