In reference to the guitar window, I believe it would be useful to have the possibility of creating a “custom” guitar tuning available. We already have tunings for all types of guitars (EADGBE variations), the violin, ukulele, mandolin, banjo, bass etc. In my unique case my particular guitar tunes BEADG and it would be great if I could use the virtual guitar to learn tunes on my particular instruments. With custom settings, all kinds of string instruments players of the world could benefit.