Gangs of youths who normally gather on a popular city thoroughfare have been driven away from the area by classical music.
West Midlands Police said piping the music over a public address system "had an unexpected affect on anti-social behaviour" on the pedestrianised ramp in New Street, Birmingham.
The stretch of pavement, which leads into the Pallasades shopping centre and the city centre's main railway station, is known locally as a meeting point for groups of young people.
Police said the speaker system was upgraded last month in a bid to create a positive atmosphere for shoppers but within days officers and local shopkeepers noticed that the number of youths gathering on the ramp had dropped.
When the music was stopped temporarily, the groups returned.
Pc Dominic McGrath, from the city centre neighbourhood policing team, said: "From experience, we know that areas where there are lots of people which are well kept experience fewer crimes and instances of anti-social behaviour, but we've been surprised by the effect the music has had on young people.
"Since the scheme went live, fewer young people are gathering on the ramp and we've seen a dip in the number of people who are asking us to move them on. Clearly, they don't like our choice of tunes."
The address system is used for sharing policing information and playing music between 9am to 9.30pm during the week and 12pm to 9.30pm at weekends.
Pc McGrath added: "We'd love to use it more, but with two hotels close by, we don't want to disturb guests.
"After all, the initiative was designed to create a positive impression of the second city."