This is a perennial favorite of music students. Let's look at a few key terms and concepts.
Canon is a melody that accompanies itself at a staggered interval. Row, row, row your boat is a well-known example. In this canon the melody, played by the violinists, follows itself in two measure intervals.
Ground Bass is the violoncello melody that repeats its 8 note pattern throughout the piece.
Cembalo or continuo is the chordal accompaniment that is improvised behind the violins. In this video it is played by the organ and the lute. Notice that the cembalo left hand outlines the ground bass.
Other notable orchestral canons can be found in J.S. Bach’s Musical Offering. The canons in that suite of pieces feature 2 violins chasing each other around accompanied by the continuo.
You've got to learn your instrument. Then, you practice, practice, practice. And then, when you finally get up there on the bandstand, forget all that and just wail.
I'm a professional pianist and music educator in West Toronto Ontario. I'm also a devoted percussionist and drum teacher.