Beyond the classic archetype: the relation between spiral structure and star formation in 
galaxies

I will review our modern understanding of the nature of spiral structure and give a brief summary 
of spiral arm dynamics, focussing in particular on how gas flows driven by spiral features 
organize and rearrange the gas reservoirs in galaxies.  As a result of gravitational torques 
exerted on gas by spiral perturbations, these structures bring recently accreted material from 
the outskirts of galaxies to their very centers, building the molecular reservoir for star formation 
on the way and contributing to the growth of black holes, the build-up of bulges and the feeding 
of central starburst activity.  I will also describe the emerging picture for how spiral arms directly 
impact the amount, location, and regulation of star formation in disk galaxies.  While these 
structures have long been appreciated for their vibrant, visual connection to the sites of recent 
star formation in nearby galaxies, we are only now beginning to understand the intimate role of 
spirals on the organization of gas down to the scales of giant molecular clouds -- the seeds of 
star formation.  Following a summary of recent results from the spatially-extended cloud-scale 
PAWS survey of CO(1-0) emission in M51, I will highlight new avenues of exploration opening in 
the era of ALMA and MUSE.