John Landstreet -Univ. of Western Ontario Magnetic Ap stars in clusters The great variety of magnetic fields and chemical compositions found in A and B main sequence Ap-Bp stars has been very difficult to understand. There may be considerable evolution of these characteristics even during the main sequence. However, neither real or evolutionary ages for such stars can easily be determined. In an effort to connect time with other characteristics, a group of astronomers is obtaining magnetic and spectroscopic observations of cluster Ap-Bp stars with FORS1 at ESO. We hope to expand this project with Espadons. This talk will discuss the motivations for this survey and some of the first interesting results. Monday, July 26th 2004, at 11:00