classical
Without specific details about the advert in question, it's difficult to identify the exact piece of classical music being played. Many adverts feature well-known classical pieces, such as Beethoven's "Ode to Joy," Vivaldi's "Four Seasons," or Bach's "Air on the G String." If you can provide more context or details about the advert, I may be able to help identify the music more accurately.
The Four Seasons, Summer, third movement.
The intended tempo for any classical music piece is determined by its composer. It can be slow, fast, or anywhere in between.
Rossini - William Tell Overture
About 20 minutes.
The texture of a piece of music is it's 'thickness'. For example, a music played by only a flute wouldn't be as textured as a piece of music played by an orchestra.
Classical music was the music composed between 1750 and1830.
Guiseppe Verdi
A fork or knife
One famous classical - or rather, Romantic era - piece of music depicting the sea is The Hebrides (Fingal's Cave) Overtureby Felix Mendelssohn.
A ten piece band, or in classical music a small chamber orchestra.