search for: first_artist_without_upd

...round a bit and discovered alias_method_chain, so I finally ended up with: class Duo < Artist belongs_to :first_artist, :class_name => ''Artist'' belongs_to :other_artist, :class_name => ''Artist'' def first_artist_with_update= (first_artist) self.first_artist_without_update = first_artist update_name # sets name to first_artist.name + other_artist.name end alias_method_chain :first_artist=, :update ... end Thinking that was a pretty cool way to extend a method, I went back and tried to use the same scheme for Musician, but there I get the missing method...