  We present an unprecedented measurement of the disc stability and local
instability scales in the luminous infrared Seyfert 1 host, NGC7469, based on
ALMA observations of dense gas tracers and with a synthesized beam of 165 x 132
pc. While we confirm that non-circular motions are not significant in
redistributing the dense interstellar gas in this galaxy, we find compelling
evidence that the dense gas is a suitable tracer for studying the origin of its
intensely high-mass star forming ring-like structure. Our derived disc
stability parameter accounts for a thick disc structure and its value falls
below unity at the radii in which intense star formation is found. Furthermore,
we derive the characteristic instability scale and find a striking agreement
between our measured scale of ~ 180 pc, and the typical sizes of individual
complexes of young and massive star clusters seen in high-resolution images.
