Now read that article outloud and record it.
Reasonable to the medium
or means in this case however lets people follow the common practice
of putting the credit on the record sleeve /CD jewel case.
"Reasonable" doesn't have to mean "common practice". How about
out the names at the end? It's going to be a worse ratio than pages of
print (you can't read something in a small font size, after all), but
it's still doable (especially with text-to-speech converters, so you
don't have to waste time reading all the names). Reading credits at
the end is pretty common practice for radio broadcasts, anyway, why
not do the same for CDs?.