The interval is a perfect fourth.
Im pretty sure its A but it could also be C
I believe it’s strings (sorry if I’m wrong)
<span>Hildegard of Bingen was also popularly known as St. Hildegard. </span><span>She was a musician and a composer, popular for her creation of gregorian chants that consists of different ranges and variations different from the usual gregorian chants.
I hope this helped you.</span>
