I am trying to replicate an older score, where the the clef changes at the beginning of the line. However, unlike Lilypond's default, the old clef and the key signature are printed and then immediately following that, the new clef is printed before any notes appear.
There is a snippet which shows how to do this at the beginning of a piece (http://lsr.dsi.unimi.it/LSR/Item?id=792), but I can't see how to do it mid-piece.
I even tried inserting a dummy note to do a clef change mid-measure, but that makes an unsightly gap between the key signature and the new clef.