Violette,
There are many ways to make a profile interesting. The cadence and resistance are two factors that an instructor can use to make the ride more realistic and add variety. The basic drills done on a spinning bike are as follows:

Seated Flat
Standing Flat
Seated Climb
Standing Climb
Running with Resistance

Then, there is the combination of a Seated Flat and a Standing Flat, which are known as "Jumps." Jumps are done at a cadence of 80-110 RPMs. Next, there is also the combination of a Seated Climb and a Standing Climb, which are known as "Jumps on a Hill." These jumps are done with a heavier resistance which causes the cadence to slow between 60-80 RPMs.

You can vary the time, speed, resistance and positions. The combinations are endless. Have you considered becoming a certified instructor yourself? You've been spinning for 4 years and are bored with the current instructor(s) you are experiencing. Perhaps it's time to put yourself out there and show them how it's done.