RE: How to center an instrument name between two clefs

[Bertalan Fodor]

I think the trick is to use the property PianoStaff.instrument.
See my template:

staffPiano = {  
        \new PianoStaff {
                \property PianoStaff.midiInstrument = #"acoustic grand"
                \property PianoStaff.instrument = #"Piano"
        <<
                \new Staff {
                        \clef treble
                        \notes { c }
                }
                \new Staff {
                        \clef bass
                        \notes { c }
                }
        >>
        }
}

\score {
        \staffPiano
}