Markup in a variable

[Mark Probert]

Hi, all.

I'm getting myself confused. I have an include file -- foo.ily -- and I 
want to define different instrument names for later use, like

 altoSax = { \markup { \fontsize #-2 {
  Alto Saxophone \concat { E { \raise #0.5 \teeny \flat }}}}}
 tenorSax = { \markup { \fontsize #-2 {
  Tenor Saxophone \concat { B { \raise #0.5 \teeny \flat }}}}}

but when I do this I get an error "markup outside of text script or 
\lyricmode."

What is the correct way to do this kind of thing?

TIA 
 .. mark.