bert - they sure noticed the switch. My first class was all women; 23 of them. One of the ladies did a drawing for one of the long poses, of me from the knee to the navel. It apparently pleased her instructor because he hung it on the wall of the hallway leading to the art department. Thankfully the drawing did not depict my face, so my genitalia was anonomously posted for the duration of the semester.

It was a coincidence that I was also booked to play a concert at that same college, and the ads for that show were all over the campus throughout the time I spent modeling. No one ever seemed to make the connection at first (I presume they didn't recognize my photo since I was wearing clothes in the pic) but the last week I was there the instructor figured it out, and asked if I would pose with my guitar for the last class. Thankfully, I got to do that class fully clothed.