\tempo \markup \rhythm

[James Harkins]

Documentation says:

\relative {
  \tempo \markup {
    Swing
    \hspace #0.4
    \rhythm { 8[ 8] } = \rhythm { \tuplet 3/2 { 4 8 } }
  }
  b8 g' c, d ees d16 ees d c r8
}

I said (in a "globalxxx" variable):

globalChorale = {
  \numericTimeSignature
  \key ef \major
  \time 7/4 s4*14
  \time 5/4 s4*5
  \time 7/4 s4*21
  \time 5/4 s4*5
  \time 7/4 s4*7
  \tempo \markup { \rhythm { 8 } = \rhythm { 8 } }
  \time 6/8 s2.*2
  ... more time sigs
}

Lilypond does not like it one bit:

./common/globals.ily:139:28: error: wrong type for argument 1.  Expecting 
music, found (ly:make-duration 3)
  \tempo \markup { \rhythm 
                           { 8 } = \rhythm { 8 } }

Now I didn't think I differed *so much* from the docs example, but apparently 
I've done something wrong.

What's up?

hjh