I couldn't do it to classical music... too many movies did a sex scene with classical music in background and i would laugh all the time.William Tell Overture (Theme from the Lone Ranger) by Rossini
The 1812 Overture by Tchaikovsky
Ride of the Valkyries by Wagner
La Habanera from Carmen by Bizet(?)
Marriage of Figaro Overture by Mozart
The Barber of Seville by Rossini
The William Tell Overture would make me giggle -- too many potential jokes. But the others are great choices.
On the other hand, I have some very good memories about Basque musician Hevia.