Percent in lyrics

[Moray Allan]

Sorry if this is answered somewhere in the documentation, but I can't
find it anywhere:

In lyrics mode, how can I enter a literal % without Lilypond
interpreting it as a comment? - Escaping with backslash doesn't help.

(Before anyone suggests it, no I can't just write 'percent', since the %
is actually a symbol in a harmonic analysis. ;)

Alternatively, can someone tell me if this just isn't possible, and I
can presumably set something up to hack the TeX output from Lilypond.

Thank you for your help,

-- 
Moray Allan