Recently I saw a "pop-up" concert performed by my friend Lenni Jabour at a big-box book retailer named Indigo in downtown Toronto. A pop-up show is an unannounced event in a public space, and in Lenni's case, she has chosen to commandeer pianos lying dormant in public places–without permission.

The shows are one part civil disobedience and three parts soulful art designed to provide an unexpected lift to people who happen to be at the right place at the right time.

The piano at the Indigo store in the Manulife Centre in downtown Toronto was a perfect target for Lenni’s spontaneous show. It is a beautiful K. Kawai grand piano used mostly for decoration. As Lenni approached the piano, shoppers started to take notice. As she started playing, an Indigo employee wandered over, curious to see who had taken over their piano without permission.

But as Lenni played, the Indigo employee realized Lenni's intentions were benign and let her perform. Shoppers watched as she sung five songs, each to an ever-growing round of applause.

At the end of the short performance, the cashier from the Indigo store came over to thank Lenni for such a wonderful concert and handed her an Indigo gift card as a small token of the store's appreciation.

Neither the employee nor the management of the store had been given advance notice of Lenni’s intentions so I’m fairly sure the Indigo employee was simply acting on good judgement alone.

Now contrast the Indigo experience with a similar pop-up concert Lenni gave at a high-end shopping mall called Hazelton Lanes–also located in downtown Toronto. Within a few minutes of Lenni's performance, a security guard approached and asked her to leave, robbing Hazelton Lanes of a delightful free concert for its shoppers.

So what would your employees do if you were not around to provide direction in an unexpected situation? I'm fairly sure there is no rule book for how to handle a pop-up concert at either Indigo or Hazelton Lanes, yet one employee chose to use common sense and reward Lenni with a thank-you gift and the other asked her to leave.

I’m a big fan of having an employee manual, but sometimes you can’t cover every eventuality that could arise in your business. What direction do you give your employees for situations where they need to use their judgment?

I used to own a research company and we hosted a special event for our customers each year. The event was a once-a-year opportunity for us to meet our clients and show off our latest thinking. Every person in the room was a VIP to our business. In the early days of running the conference, I would try and map out every possible thing that could happen and give my employees rules for every problem that might occur.

The set of rules became longer and longer each year and inevitably things came up that I just couldn’t have predicted. After seven years of running the event, I scrapped the rule book, and now I give people one simple analogy to guide their behavior: "treat attendees as if they were guests in your home."

With a guiding philosophy of entertaining friends, it became clear to everyone how to act. If an attendee needed to store their bag, our staff offered to keep it safe; if an attendee was shy, one of our team members would engage them in some light banter to take the edge off; if a few people were meeting for a drink, our staff member would pick up the tab. With a philosophy of how to behave instead of a set of rules, employees became more natural in how they interacted with attendees. Gone were the awkward pauses while an employee tried to recall the correct response to a situation.

My employees didn't need a rule book; they needed an operating philosophy.

Indigo’s mission is: "To provide booklovers and those they care about with the most inspiring retail and online environments in the world for books and life-enriching products and services," and their first operating value is to "add joy to customers' lives." So it really wasn't surprising that the Indigo employee let Lenni play.

Do your employees know when to throw out the rule book and let your philosophy guide their responses to the unexpected?