Perhaps the best number in this is Fred and Ginger's dance 'n tap on roller-skates, but the terrific Gershwin score helps a lot (including 'Let's Call The Whole Thing Off', 'They Can't Take That Away From Me' and several others).
This is one of the pair's best, with the usual strong support from Edward Everett Horton, Eric Blore and Jerome Cowan. A silly plot, with Astaire as a Russian ballet dancer (not really Russian, his real name is Peter P Peters!) and Rogers as a musical revue star, who meet and get embroiled in a fake marriage run-around. Horton plays Astaire's fussy manager, Blore plays a pompous hotel manager (the scene in the jail prompting the cop to ask 'what is this, a spelling bee?' is hilarious), and Cowan plays Rogers' manager (a chap distractingly named Arthur Miller).
'Shall We Dance' showcases Ginger Rogers in particular and gives her chance to shine; Fred Astaire remains the usual unattractive pest until he breaks into singing and dancing; and the finale, with a bevy of masked honeys who look like Ginger, has a certain originality. A great team at their very best.