@jennythelib - Yoga and pilates classes are great, but if you're pressed for time and need an "everything" class, those are becoming more and more common.
My gym, for instance, has a class called "Body Vive" that's a little bit of everything. There is a short aerobics segment and a strength training segment. The strength training includes core strengthening exercises that are sort of yoga/pilates-inspired--set to music, of course.
I really like that class because I do like to get in a good stretch and good back exercises, but I don't really like to do a whole hour of yoga. (Yawn. Just not my cup of tea.)