\version "2.12.2"

myTitle = "Song Title"
myTempo = "120"
myTempoNote = "4"

\header
{
    title = \markup
    {
        \override #'(style . cross) { \note #"4" #UP " = " \myTempo }
        \hspace #7 \myTitle \hspace #7
        \small { "written by some guy..." }
    }
}

\new Staff { g'1 }