Text beside staff

[Ahanu Banerjee]

Hi,

I'm typesetting a book of études. I am currently putting the number of the
etude (1-2 digits) in the header as a title, but I would like to put it to
the left of the first staff, in the indented white space. It should be
center-aligned between the left margin and the first staff, and vertically
centered about the staff.

Can someone provide a tidy way to do this?

Thank you!!

\version "2.20.0"
\header {
  title = "1"
  subtitle = "A female deer"
}

{\repeat unfold 16 c' \break
\repeat unfold 20 c'}