While researching for the chapter on music boxes in my forthcoming book
"The Golden Age of Automatic Musical Instruments" I timed a number of
discs on various Reginas.

The average playing times that I thought produced pleasant musical
results were just a little less than a minute for the 15-1/2", and
about two minutes for the 27", although there are probably some discs
that should play a little faster or slower.

Art Reblitz