This instrument is called”Alwaza” used in blue nile tribes. The guitar is in “D” tuning. I play guitar in this very fun and forgiving tuning style and it is simpler than it looks, yet has a full orchestrated sound, an open, flowing full major sound. It’d be a fine musical meditation with cosmic loftiness using the Alwaza flut and “D” tuning. Richie Havens uses “D” tuning in his version of “Here Come The Sun” https://m.youtube.com/watch?v=VBbXKsKXyNU