I have a restored Tangley A-43, Ser. No. 957.  It's label says:
1 psi., blower speed 700, pressure range 5/8 to 1 psi.  It has
a spring valve regulator on it and will play all notes at about
1/2 psi or just above.  At 1-1/2 psi it can be heard for about five
blocks.  If I play it here at the house, kids come with quarters from
blocks around, wanting ice cream.  :-)

It is powered by a Spencer Turbo Compressor turning 3500 rpm, capable
of producing 12 CFM (cubic feet per minute) at 35 ounces per sq. inch.

I plan to have my calliope in the Texas State Fair parades, on the
opening day through downtown Dallas, and 24 nights on the fair grounds
this fall.  It was a big hit in the Mesquite Rodeo Parade last month.

Don Bryant