The note about mailing rates for music rolls in today's MMD left me
confused.  In looking at the USPS website, I don't find any definition
of what has been discussed here as "M-Bag."  So I assume -- possibly
incorrectly -- that the term is slang for an inexpensive international
shipping rate.

For domestic (intra-U.S.) shipping of music rolls it has long been
possible to use the rate commonly  known as "book rate," which is
generally the cheapest rate for shipping rolls over distances, because
it is based solely on weight and not on distance.   A long-standing
decision of the Postmaster General has classified music rolls as "sound
recordings," one of the classes specifically stated as eligible for
book rate.

My reading of the current domestic rate manual which Robbie quoted
tells me that nothing has changed with regard shipping music rolls
inside the U.S., that book rate still applies and is still in most
cases the cheapest rate you can get at the post office.  The only thing
that seems to have changed is the name of the beast.  What used to be
called "Book Rate", until being fancified a couple of years ago into
"Special Fourth Class Rate", is now called "Media Mail (Book Rate)"
in the current manual.

So continue to insist to your post office clerk that your package of
music rolls is eligible for book rate -- because they are sound
recordings, which they are.  (NOT because they are sheet music, which
they are not.)  In years of shipping music rolls I never encountered
any resistance but once, and when I asked the doubting clerk to haul
out the domestic rate manual, the reply was "Okay, I'll take your word
for it."

Matthew Caulfield