Invisible note lines?

[bb]

For a backing track I want a melody line and chords printed on a lead
sheet - standard with lilypond.
But a midi should have an aditional kickdrum/bassdrum for rhythm. The
notes should not be visible on the lead sheet but to hear in the midi.
Is it possible to add notes for midi but invisible on the print?

Certainly I can assemble one lilypond file for the lead sheet and
another one for the midi. But that is not really smart. It is not
comfortable to have to change two lilypond files for corrections etc.

Regards BB