before going on to name various cities (e.g. Kampala, Milan, Delhi, Johannesburg), followed by the station's slogan and the Greenwich Time Signal. This was heard throughout the network with a few variations – in the UK the full service name was spoken, whereas just the name of the BBC was used outside the UK. The phrase "This is London" was used previously in place of a station slogan. The tune "Lillibullero" was another well known signature tune of the network following its broadcast previously as part of the top-of-the-hour sequence. This piece of music is no longer heard before news bulletins. The use of the tune gained minor controversy because of its background as a Protestant marching song in Northern Ireland. The Prince of Denmark's March (commonly known as the Trumpet Voluntary) was often broadcast by the BBC Radio during World War II, especially when programming was directed to occupied Denmark, as the march symbolised a connection between the two countries. It remained for many years the signature tune of the BBC European Service. In addition to these tunes, the BBC World Service also uses several interval signals. The English service uses a recording of Bow Bells, made in 1926 and used a symbol of hope during the Second World War, only replaced for a brief time during the 1970s with the tune to the nursery rhyme "Oranges and Lemons". The morse code of the letter "V" has also been used as a signal and was introduced in January 1941 and had several variations including timpani, the first four notes of Beethoven's Fifth Symphony (which coincide with the letter "V"), and electronic tones which until recently remained in use for some Western European services. In other languages, the interval signal is three notes, pitched B–B-C. However, these symbols have been used less frequently. Time The network operates using Greenwich Mean Time, regardless of the time zone and time of year, and is announced on the hour on the English service as "13 hours GMT" (1300 GMT) or "Midnight Greenwich Mean Time" (0000 GMT). The BBC World Service traditionally broadcasts the chimes of Big Ben in London at the start of a new year. "This is London" A BBC News report would begin with its station identification phrase "This is London" or "This is London calling". The phrase has become a trademark of the BBC World Service, and has been influential