Hi Steve, In an include file, I have the following:
showMMRs = { \set Staff.keepAliveInterfaces = #'( rhythmic-grob-interface multi-measure-rest-interface lyric-interface stanza-number-interface percent-repeat-interface) } letStaffVanish = \set Staff.keepAliveInterfaces = #'() showLyrics = \set Lyrics.keepAliveInterfaces = #'(lyric-interface text-interface) letLyricsVanish = \set Lyrics.keepAliveInterfaces = #'() I use those to turn staves and lyrics on/off. Hope that helps! Kieren.