Terminology:

Augmented Second - 
An interval between the first and second note of a typical Major scale that has the second note raised by one half-step higher than it naturally appears.

Double Reed Instrument - 
An instrument in which two pieces of cane vibrating against each other create the sound/resonance.

Doublings - 
The same notes are played by multiple instruments across the orchestra to increase weight, size, and presence.

Half-Step - 
The smallest distance from one note to the next on a piano, guitar, or other western instruments.

Rhaita - 
https://www.youtube.com/watch?v=Svc-8DBCIPs&list=RDSvc-8DBCIPs&