Yes, it is. Lots of classical music is played by a symphony orchestra. There are thousands upon thousands of classical orchestral works - too many to list here.

It was one of the first jazz compositions to be performed as an orchestral classical work. The original scoring was for dance band; it was performed by Paul Whiteman's orchestra. The piece was later rescored for symphony orchestra.

Maestro is the usual reference to the Conductor of the orchestra. Maestro roughly means "Master" ... the orchestral conductor is the master of the orchestra leading them through the pieces they play.

It is a work for orchestra and a soloist.

Classical, rock, and heavy metal use a significant amount of orchestral elements. It depends on the artist's style, as not all artists of rock and metal will use an orchestra, of course.