As to recommending music OCR software there are several very good
programs out there but you get what you pay for.  Even with the most
advanced and expensive software you will likely have to compare the
software output meticulously with the printed score.  More modern score
typefaces work best, with older 19th century ones remaining potentially
problematic.

Some software can now also scan all the dynamic "p" "FFF" and crescendo
lines and produce a MIDI with very lifelike performance dynamics
straight from the page.  Even these, despite their frequent excellence,
will always lack something.  Playing of music notation just like the
recitation of the printed word requires human interpretation and it is
for this reason that automated text reading software can make a good
effort but usually only go so far.

You should shop-around to see how the functionality of the software
matches up with your own musical ability.  If the software interface is
geared to folk who are very proficient musically then your decision to
purchase may be affected depending upon your own personal skill level.

To make rolls via OCR-scanning I would first recommend becoming very
proficient at music reading and also very adept at MIDI sequencer
software use as these are the two areas that will significantly speed
up your ability to make music rolls via this method.  The more familiar
you become with stuff like the Cakewalk program the quicker this
becomes, the quicker you become with reading music proficiently the
quicker you can amend errors and note lengths.

Any sheet music to MIDI OCR output will still need heavy sequencer
editing to make acceptable music rolls and will never be a means to an
end in the mechanical music field unless one likes mechanical music to
sound particularly mechanical that is.  If one wants to muck about with
organettes "playing" Entry of the Gladiators on 14 fascinating notes,
strangely condensed into 23-and-a-half bars of music, this might suffice.
For piano rolls, orchestrions or fair organs and the like a higher
standard is warranted.

I faced all these problems when I decided to earnestly learn to use
software to program rolls.  After faddling about with music scanning
software I realized that generally it was a waste of time as what
really consumed the time was the post-scan editing time you need to
expend to make acceptable music rolls.  I forced myself to spend hours
every evening for over a week just using Cakewalk and getting proficient
with its use.  Considering time expended vs. time saved it was more
than worth the enforced effort.

You will need to brush up your music reading ability as without this
you may as well be typesetting a Chinese book: you'll make it look
nice on the page but half the words might be wrong for all you know.
For text, the eye may glance over a typographical error but for music
the ear is not quite so forgiving.

Like all things, making music rolls is not hard once you have the
few basic skills, great fun and well worth the time expended in
experimenting.

Regards
Adam Ramet, UK