For each person who sees buskers as a nuisance and noise pollutant, many more see them instead as a welcome interruption from urban routine. Whichever position we take, buskers have a powerful impact on our day-to-day experience of a city — from the half-hearted accordion players on bridges across Europe, to the exquisite performances in New Orleans' French Quarter.

Local governments in some cities have begun to catch on — buskers have even been described as the "perfect placemaking tool." But how can cities make the most of them, without stifling the spontaneity that makes them what they are?

Intimate encounters

Busking — usually defined as musicians or actors entertain people in public spaces in exchange for donations — is seen as one way of boosting sensory engagement with a city, and consequently it's getting greater attention from city authorities.

As I write this article on a cross-border train on the edges of Europe, one enterprising young man with a guitar has taken advantage of the break to entertain passengers waiting railside. In minutes, a crowd of all ages and nationalities has gathered around him, intently listening and chattering.

These occasions are the key to the charm of busking — the moments of connection that unexpected theater can create between strangers. Alienated urban dwellers yearn for these rare moments of spontaneous interaction, and often intimate encounters, between the eclectic mix of people sharing the same streets.

Storytelling on trams

Busking often has a different flavor in each city, absorbing local traditions.

For instance, the Colombian capital of Bogota has a deep-rooted history of oral storytelling, and on Sunday afternoons the city's "cuenteros" (storytellers) spill into public squares across the city. Crowds soon gather around, open-eared. These spaces are cherished as a way for people from different parts of a divided country to come and tell their story and their own experience of the city.

Bogota's Transmilenio bus system has been hailed by urban activists worldwide as a bold and positive step. However, most interestingly, when a survey raised dissatisfaction with the service, aside from pragmatic improvements like extra bathrooms, 15 percent of respondents also thought that authorizing street musicians in stations and at gates could improve the passenger experience. Another 9 percent also wanted to see the city's cuenteros during their commute.

Busking as urban policy

Busking used to be something penniless students would try their hand at for beer money. But times have changed.

Some cities — particularly those keen to brand themselves in the image of Richard Florida's "creative cities" — have made attempts to formalize the busking scene and promote the city's buskers as deliberate policy tool. London's transport authorities now even have an annual busking competition, a busking academy and dedicated website (buskinlondon.com).

Closer to home, groups in Dallas are trying to "fill its streets with music" and cheer up miserable commuters by paying street performers an hourly wage.

Busking has traditionally been a legal gray area — one that cities are now trying to clean up. In Washington, D.C., busking was banned on the Metro, causing one musician to take them to court in the name of freedom of speech.

At minimum, there is usually a code of conduct for buskers. Others make performers audition for a permit. But cities over-regulate at their own peril — as busking advocates have pointed out, buskers are wildly popular with tourists and are a cheap and easy placemaking tool in an era of ambitious and expensive "placemaking" interventions.

Regulating the songbirds

The noises we hear can make a city — Turkish novelist Orkhan Pamuk once called singing street vendors the "songbirds of the streets."

In an era of place marketing and "creative cities," it is no wonder buskers have been appropriated as a tool by policymakers. But can the "buzz" of busking be engineered by such detailed codes? Or is this sucking life out of what was a rare moment of spontaneity intervening in the steady routine of our urban lives?

Regulators will regulate, but they must take care in not stifling the democratic and improvised nature of the busking tradition, and sterilizing its contribution to city life.