Mapplethorpe's work, especially the X portfolio, was very much about shock value, although much of it is highly informed by classical art - there was a book put out a year or two ago showing his nudes in the context of the 16th to 18th century engravings that inspired his photographs. Robert Mapplethorpe and the Classical Tradition is the title, if you have the chance to look for it. Even the classical stuff, which is HIGHLY formal, has some of the shock value, showing a nude black male dancing with a clothed white female, for example, but that is as much a political statement about the times in which he lived and worked. In all, his work is very multi-layered, and if you allow yourself to look past the shock value, there is something there.