According to teachers who spent time in Joe and Clara Pilates’ studio, there weren’t necessarily levels of exercises. A student came in and worked a few times with Joe or Clara, and then came in several times a week and did as much of their workout as they knew, with Joe occasionally delivering a command, a correction, or sometimes, a new exercise. Students were expected to know what to do, how to do it right, and how to work the equipment. There weren’t the quite concentrated one to one or duet or trio sessions or more dilute mat or apparatus classes with which we are familiar today.
When teachers needed structure, to create a system a student could study and memorize, teachers created levels. What this really means is that anyone, really, can do any level of exercise; the real substance is not in the level but in the execution. More importantly, the hardest, most challenging, most demanding, most interesting (and in many of our opinions, absolutely the BEST) Pilates exercises are the ones labeled basic!
The reason you do basic exercises first is that they are the ones you need to do for the longest (read: always). Not only do students need to do them first; we need to treat the entire basic system, on all apparatus, as a balanced diet of Pilates. (A note: it is also true that not even every basic exercise suits every body. However, the family of beginner exercises is still the starting point). All other exercises are carefully chosen supplements.
A great teacher gives you what your body needs (which by the way, sometimes you won’t exactly love in the moment.)