On Sat, Feb 15, 2014 at 5:42 PM, Renato <rennabh@gmail.com> wrote:

----but I can't see how to declare
Rosegarden as master in the preferences (nor Ardour as slave) -

Session > Properties > Sync .... choose the external clock source

Then use the clock source button just right of the transport buttons to switch between the internal clock and the chosen external clock source.

Right now I have a tempo ramp up defined in rosegarden, and as the
transport goes through it I can see the BPMs changing in Rosegarden,
but not in Ardour nor in Hydrogen...

ardour does not pay any attention to JACK tempo information.