Cue about relaxed shoulders, elbows bent towards the earth, hand position one, spine straight, abs sucked in a bit. Second song should usually be a seated climb. Cue to keep increasing resistance until the legs are on the beat of the music, working the whole circle. This progression provides an ideal and reasonable warming up process. Do all one legged stretches OFF the bike completely.
Most new instructors are in the habit of talking too much.
This is annoying, for cycling classes are intended for participants to let themselves go and have their own ride. They can't do this if they're constantly being told what to do and made to change riding style, technique, or position every eight counts. Don't be nervous. This is a cycling class, not Congress or cancer. This is a ride, not a series of different, isolated exercises.