Extending tempo

The Tempo marking may include a markup to create a more complex marking indicating tempo for more complex rythms.

\version "2.24"

% Create a more complex Tempo marking
% The markup-command can be used to create a non standard Tempo
% Be aware that this Tempo does not have influence on a MIDI-export

 \relative c'' {
  \tempo \markup {
    \concat {
      \bold "Andante appasionata "
      "("
      \lower #-0.5 \note {4} #UP
      " ("
      \lower #-0.5 \note {4.} #UP
      ") = 42)"
    }
  }
  a1
}