[CM] passing variables as fomus event-marks

[Michal Seta]

I generate lists of frequencies which I would like to notate in
lilypond and write the frequencies under each note.  The following
code fails with:

define process notate-scale(str)
  run for i in str
    begin with
      k = keynum(i, :hz),
      output make(<note>,
                  off: now(),
                  note: k,
                  dur: 1,
                  marks: {{:textnote i :down}}
                  )
      wait 1
    end
  end

>>> Lisp runtime error: Found (:TEXTNOTE I :DOWN), expected valid/unique mark in MARKS slot of note at offset 6.0, part NIL

(BTW, copying and pasting between Grace and the rest of the world, at
least on my Linux version, is impossible).

I am sure that I am overlooking something simple because the same code
works if, instead of the local variable, I pass a string in quotes.  I
would appreciate any light ...