Singer Mick Jagger, musicians Charlie Watts and Keith Richards of The Rolling Stones perform at The Honda Center on May 15, 2013 in Anaheim, California. - 

The Rolling Stones are set to play a live show in Chicago tonight as the summer concert season gets underway. This used to be the time of year when artists went on the road to help boost their record sales.  But in the digital age, it’s the other way around; for a lot of musicians now, putting out an album is an excuse to take the stage.

For 94 years, the state of North Dakota has run a public bank. It acts like a mini-Federal Reserve that subsidizes loans based on local priorities. The bank helps local entrepreneurs, students and others all while generating a profit for the state treasury. This weekend, attendees of the Public Banking Conference in San Rafael, California will gather to re-think the global banking system. They hope to spread North Dakota's time-tested financial idea.

Follow David Brancaccio at @DavidBrancaccio