{
\relative c' {
   \clef treble 
   \time 4/4
   \key c \major
   <c e g>1_\markup { \concat { \translate #'(-3.5 . 0) { "C:   I" \hspace #7 "vi" \hspace #6 "IV" \hspace #6 "V" \hspace #7 "I" } } }
   <a c e a> <f c' f a> <g b d g> <c e g> \bar "||"
} }
A '50s progression in C