The fast-food chain has found that playing classical music promotes more acceptable behaviour late at night.

Classical music has often been used as a method of dispersing loitering teenagers at train stations, with Blacktown train station in Sydney using Mozart and Beethoven to dispel young people congregating in the area. But now – contrary to what you might expect if you’ve read Anthony Burgess’s A Clockwork Orange – McDonald’s restaurants in the UK have been using it to head off any troublesome behaviour from its customers late at night. Far from inciting a bit of the ol’ ultra-violence, the fast-food chain has found classical music to be an effective method of calming its late-night diners and head off any rowdiness.

“We have tested the effects of classical music in the past and played it in some of our restaurants as it encourages more acceptable behaviour,” a spokesperson for McDonald’s said in a report by The Sun. “Typically, classical music would be played from early evening onwards and, in some cases, on certain nights in a small number of restaurants.”

The music reportedly “varies from restaurant to restaurant” with Liverpool, Cambridge, Huddersfield, Swansea, Southampton and London branches all using the crowd control technique.

The technique is also being used in Glasgow’s Argyle Street branch, notorious for rowdy customer behaviour. Police had been called into Scotland’s busiest branch 200 times in 14 months before the managers began pumping classical music through the store’s stereo, Daily Record reported.

But the idea isn’t anything new. A McDonald’s in downtown Dallas in the USA that was plagued by gang violence in the 90s saw arrests at the location more than halve once it started playing classical music.

Judging by the responses on Twitter, classical music in McDonald’s has been bemusing customers for some time.

“Sat in a grotty #McDonalds listening to classical music surrounded modern art, very confusing,” wrote Jonathan J in 2015.

“Never imagined McDonalds to play classical music! #classy #McDonalds #whatisgoingon” wrote Lakshman Ganatra.

More recently Diarmuid O’Neill tweeted from Liverpool: “Just went to a #Mcdonalds that played classical music and did table service…. It’s [sic] was very strange and surreal experience.”